I need advice on whether or not to upgrade, stay where i am (at Sonar Producer 7), or use another company/system.
 
I have a PC running XP Pro and using Sonar Producer 7. I have used Sonar for about 12 years and I'm very sad to see Gibson do what they're doing. But to stay on point, I'd like to be able to use newer and better versions of Waves plugins and possibly use Melodyne as well which I'm not sure using any recent version would work with what I have (Producer 7).
 
So to all of you who come here and read this, what would you do:
1. upgrade to the latest version of Sonar - like SONAR Professional
(if so, what would be the most stable OS version of MS that I should have?)
2. Should I just stay where I am (at Producer 7) and try to finish my projects (there are many)?
3. Or should I switch to another system (Pro-tools, Ableton, Reason, etc...)
 
I prefer not to switch as I have really enjoyed using Sonar but welcome all opinions.
 
Thank you,
Tom

I think there is quite a lot of difference between sonar 7 and current sonar. In any case the cakewalk store is no longer selling anything. So it looks like option 2 is what you need to finish your projects then either continue with 7, or move on to another platform.

There is a fourth option: buy any copy of Sonar (including Sonar Artist) you can get in any retail vendor and install it on top of S7. Any plugins you have with Sonar 7 should continue to work, and you'll have the latest engine. 
 
If you have fewer than 64 tracks, you can just buy the November issue of Computer Music and get a download of Sonar Home Studio and Rapture Session for free. 
 
Sonar 7 was my first DAW. Even after all the patches, I remember it being heinously buggy. There's no telling how long it will go unbroken by Windows updates, but given how long you've gotten away with running a 10-year old version, the odds look pretty good.

Becuase you are using one of the very old versions changing to a new version of Sonar would be just as much learning curve as switching to a different brand. But that said, IF Sonar is still for sale it will probably be selling for real Cheap as there is no longer support etc. There's no way any retailer could sell it for full price. But I guess there's still 99% of the retail and MI world is unaware of what happened. Most stores if you asked for Sonar used to say" What's that"? A few years from now many when told that Sonar is no longer will say " oh , when did that happen"? 
 
There is much about the new Sonar that did stay the same and if you can find a copy Cheap it is certainly what I would do. 
I'm not changing and like you have done hope to get 10 years out of this version. Don't listen to those who say "Windows updates will someday kill it" That didn't happen to you, right. so it's a myth. 

You can do what you like, but I wouldn't be buying into a dead end product, SONAR is dead. There is more to think about than just Windows, there is future hardware, future plugins, hardwae and software/plugin developers aren't going to be worried about supporting a dead DAW, and eventually you will hit the wall. Also, there is future technology advancement, as Craig Anderton has  pointed out there are big changes in the midi world coming next year, and as he also pointed out, know that SONAR is dead, it is uncertain that these new technologies will be functional in a stagnated and dead SONAR, there are many things to consider.
 
Oh, and the line of thinking that Windows wont break SONAR at some future time is itself a myth.