There's a lot of concern right now about what to do next, and nobody's more panicked than the professionals who depend on their DAW to make a living. They are rightly thinking about how to protect their businesses. To them, I say: calm down. Take a deep breath, and carefully consider your options - and, more important, the unforeseen consequences of any rushed decisions you make today. 
 
In the wider world of truly mission-critical applications, a DAW doesn't even make the list. Even if you depend on it for your livelihood. How about the software that lands airplanes in bad weather? Or that monitors you during surgery? Or tells a cruise missile what to blow up?
 
Back when I worked for a computer manufacturer, one of my customers was a nuclear power plant. Talk about software you can't allow to fail - ever. The first time I spoke with them, I was surprised at how far out of date they were with the O/S. They were having some problem with a driver. Like the noob I was at the time, I asked why they didn't just update it - the standard advice you give when you're a newly-minted software support analyst who doesn't yet know WTF he's doing.
 
That's when I first had the term "mission-critical" explained to me. They explained that they worked under strict rules set by the NRC for software changes, rules that set such rigorous requirements that it took at least two years to certify an O/S revision. My company was on an 18-month major-release cycle, which made O/S revs a moving target. They'd had to freeze their version, and they'd been working with my employer for over three years to find, fix and mitigate every conceivable flaw in it. That's why they were still using "outdated" software.
 
The point of this is this: by staying on one version long-term they were actually improving reliability. Every defect in that version had been identified and dealt with, either by getting a fix from the manufacturer or devising a workaround to avoid it. Sure, they missed out on new features. But they also weren't constantly trading one set of bugs they knew about for a new set of bugs they didn't know.
 
As Panu noted in another thread, there will be no bug fixes for SONAR but there will also be no new bugs. We know its current weaknesses and none of them are showstoppers (definition of "showstopper": a flaw that prevents users from using a key feature). We have nothing to fear from SONAR itself.
 
Ah, but what about Microsoft, you say? They could break us at any moment.
 
If you're a pro and that worries you, do what the nuclear power plant did. Take your DAW offline and freeze it in a stable state. Test all software changes on a separate computer before installing them on your mission-critical system. Don't go installing some file-conversion utility you found for free on a Chinese website. Don't play video games on your DAW. Don't tweak the registry because you saw some optimization technique in a YouTube video. Don't run anti-virus software (you don't need it, you're offline now). 
 
Now, I can hear you protesting: this is easy for you to say, bit. You're just a hobbyist. Well, I may be a hobbyist but I am just as serious about this stuff as any professional. Losing my DAW might not cost me money, but it would still be a horrible tragedy. I have no intention of risking that!
 
And although I am not a recording professional, I am a software professional. I make my living helping other people make theirs. I have to understand risks and how to mitigate them. And I am here to tell you that Microsoft is not going to break SONAR anytime soon. I know people still running SONAR 4. Think about how many changes Windows has undergone since 2004. It still works! Sure, they're missing out on all the cool features Cakewalk has added, but for them, S4 does everything they need. Namely, recording and mixing audio.
 
Picking up skills on another DAW is not a bad idea. I'll be doing the same, even if I haven't yet settled on which one to adopt. I'm just in no hurry. SONAR already does everything I could ever want it to do, and I'm confident it'll continue to do so for a long, long time.

but you know about embedded systems.. daw's ain't. hardware makers can "muck" us up also with lame-o drivers that ain't fit for purpose. I used to get NI kontakt make sonar fall over, thats how I got to know mr jones so well haha
 
so yer, 3rd party dev's have an impact hence why reason didn't have em , for a long long time.. and even now.. well they can't give a cast iron guarantee with everything.
 
it's the same with win xp, I do know a few places who run it.. I run an old pc/windows that isn't online solely to work with an eprom programmer. or with my older 8 bit machines , machines that still have IDE floppy connectors.. as the USB ones don't work properly for disk porting.
 
of course it won't fail yet.. but in time , it'll break code doing funny things, causing exception errors etc.
 
my old atari ST can still load up c-lab 20+ years on without issue ;-) . but then again it's old hardware.
 
people like to have stability, consistency and familiarity .. if you know you are gonna have to re-learn things, it's just a case of putting things off..  but there is similarities between all the DAW's I use.
 
I'm finding it amusing people are using a new DAW for all of a day (if that) and assuming x-y and z.. come back in 2+ weeks after you have seen training videos on it also.. then comment.
 
if you can claim stuff back as a business expense and you make money from it .. then it's like you are getting the software for free anyway (I'm one of many who don't).. much like a builder has to buy tools.

I hear ya, Fog. But SONAR's code can't "break". It's static. Whatever works today will work exactly the same way tomorrow. Software doesn't wear out. It can't break if it doesn't change. 
 
What can break are external dependencies and hardware, which are in constant flux. But those don't fall under the purview of the DAW itself (like they would have in your Atari). Applications are no longer responsible for defining peripherals like they once were. When the day comes when we're able to buy petabyte holographic crystalline storage devices, SONAR will address them the same way it addresses your hard drives and SSDs today: through a driver that conforms to well-defined interface specifications.
 

That was weird. Aksimet has been on a roll this past week, randomly deleting posts left and right. It deleted yours while I was responding to it! That resulted in the software telling me I couldn't submit my post. The more "intelligent" software is, the less I trust it. 
 

Just wait until Akismet deletes Sonar... 

Using Plat offline works until you need to reinstall for whatever reason then what?

That's the unknown right now.
But I'm confident may current systems are "safe".
I have numerous system images.
T

Excellent points all, bit.
 
I work in the also-heavily-regulated Medical Devices industry as a product developer, so I am no stranger to the concerns surrounding mission-critical systems. You have to develop the mindset of constructing a physical firewall, along with a redundant system set up just for testing changes of ANY kind - especially new interfaces. It's the mindset that your entire system is enclosed in a hard case, like a piece of rack equipment. For a piece of rack gear, the motto is "modify it at your own risk". And as the mod usually involves heating up a soldering iron, it's not something taken lightly. Think about the life span of a piece of rack gear and you will get an idea of the long-term value of such a proposition.
 
While I do not currently make a living out of my studio*, I have worked in studios that did and so I can identify with the difficulties that this kind of change can create. From my current armchair perspective, the pain of setting up and properly maintaining a mission-critical system would be far less than the pain of not doing it.
 
One additional thought - could Virtual Machines help in any way, perhaps as a sort of "middle ground"? 
 
*I am active, though - I do full projects for my wife's students, and of course, I do my own stuff too.
 

The first thing I'll reach for when SONAR stops working all together?
 
 
 
Wait for it.......
 
 
 
 
Here it comes......
 
 

Couldn't resist, could you? 
 
losguy: I use VMs a lot in my day job, and the main reason I do so is to be able to freeze time. I have essential tools that only work under XP, most from companies that no longer exist. I'd struggled with re-installations for years before hitting on the idea of using a virtual machine. It was a lifesaver. I will never have to worry about re-installing those tools again, or wondering if the next version of Windows will break them. Plus I can copy the whole thing over to my laptop to take my work on the road. 
 
However, there is a certain amount of overhead when you work inside a VM. Surprisingly little, but always there. It's not going to be enough of a burden to prevent you from running SONAR, but it could make a difference when you're pushing the envelope with a large project.
 
Then again, almost every project I have today would have completely killed my computer from 5 years ago, so that's sure to become less and less of an issue going forward.