Doktor Avalanche
Here's an example of the side effect of these audio improvements, lots of posts like this around the internet...
http://forums.windowscentral.com/windows-10-technical-preview/346759-build-10041-sound-drivers.html
 
My advise for anybody upgrading when it comes to the time... is to be cautious! Wait and monitor the internet.... As with any software (just like Platinum) often a lot of pain has to happen in order to get gain. It may end up that some audio drivers will need to be revised (or rewritten) for Windows 10, and Win10 may uncover driver bugs that may not have been apparent in earlier versions of Windows. And of course MS will bake in their own regression bugs to throw into the pot.

Is is really a side effect of the improvements or more that not all drivers have been updated yet for Windows 10?
But agreed, it's good advice to proceed cautiously in case the drivers that are present on Win7/8 don't yet have support in Win 10.
 

My guess is latency improvements will cause a wobble with badly written audio drivers as seen here... Windows 10 will expose flaws. Of course some drivers will need to be rewritten to accommodate for a different driver model.

Are Windows 10 ASIO drivers (which MS still recommends for DAWs) any different to Windows 8.1 from a programming perspective?

And funnily enough in contact with Focusrite about this right now...

ASIO is basically a way to interface with the Kernel audio driver.  So, a change to Windows wouldn't necessarily require a change to an ASIO driver.  Given a good driver, ASIO should continue to work the same as before.
 
On Windows Store app side...
To support the lowestLatency quantuum setting for store apps, the driver would need to advertise something about it's buffer settings.  Otherwise I'd imagine a higher latency would result.
Microsoft said a white paper was forthcoming about the low latency updates in Windows 10.  That will be useful in better understanding the changes to the audio stack.

hrm, so what this is telling me is that Cake hasn't had any developer insight into Win10? I was hoping there was some outreach there like in some previous Windows versions.

fireberd
While I will agree a clean install is usually best, I have no problems with an "upgrade" to a PC that is fully Win 10 compatible, both hardware (including recording hardware) and software. 
 
Years ago it was a debacle to do an upgrade.  Anymore its not that way.
 
As everything (Sonar Platinum and my recording hardware and other software) I've tried works OK with the Win 10 Pre-release versions,  I will do the upgrade. If everything works OK (and I expect it will) I won't go thru the hassle of the clean install.
 
 

+1. I'll do a lean install if needed but if everything works with just the upgrade I'll leave it at that.

...wicked
hrm, so what this is telling me is that Cake hasn't had any developer insight into Win10? I was hoping there was some outreach there like in some previous Windows versions.

There was a post around here somewhere by Noel about the relationship and work these guys have done with M$. 

Keith Albright [Cakewalk]
ASIO is basically a way to interface with the Kernel audio driver.  So, a change to Windows wouldn't necessarily require a change to an ASIO driver.  Given a good driver, ASIO should continue to work the same as before.
 
On Windows Store app side...
To support the lowestLatency quantuum setting for store apps, the driver would need to advertise something about it's buffer settings.  Otherwise I'd imagine a higher latency would result.
Microsoft said a white paper was forthcoming about the low latency updates in Windows 10.  That will be useful in better understanding the changes to the audio stack.

Yeah that's what I'm figuring. Maybe MS will introduce a code template so ASIO drivers can be written better. WDM drivers will probably need tweaking big time though as this will have to go through their MS's framework rather than bypass through to the hardware abstraction layer with a third party wrapper.

...wicked
hrm, so what this is telling me is that Cake hasn't had any developer insight into Win10? I was hoping there was some outreach there like in some previous Windows versions.

 
Um?  I think you misunderstood something there.  We have a long standing relationship with Microsoft  A lot of the changes in the audio stack for Win 10 center around Windows Store apps (reducing audio latency for store apps, adding midi support, etc.) We're not unaware of the changes.

...wicked
hrm, so what this is telling me is that Cake hasn't had any developer insight into Win10? I was hoping there was some outreach there like in some previous Windows versions.

Not sure how you drew that conclusion. Were most definitely in the loop with Win10 and have been in discussions with MS since much earlier on in its design. We even gave them plenty of feedback on issues to investigate.
As Keith says the low latency stuff MS is are doing has to do with the higher level audio stack (Modern apps and not desktop apps) As such it should not impact low level access like ASIO or WDM at all.
 
Most driver issues in new OS releases stem from installation problems where the installer is checking for a previous OS or relying on stuff that it shouldn't. There are exceptions like the Firewire issue but rare.