Using the evaluation copy with Sonar Producer... solid and fast.  I love 10.  

fireberd
You have to do the upgrade to get the free Win 10, from what I see reported.  You will get the Product Key with the upgrade.  You will then be able to do a clean install using that Product Key. 
 
I have Win 10 Preview installed on my backup system.  The new versions take "forever" to install but I haven't lost any user applications (e.g. Sonar and the Command Center), device drivers, etc.  I haven't had any disc problems either.  Win 10 Preview is installed on a separate hard drive (this is a triple boot system Win 7/Win 8.1/Win 10 Preview.

Thanks for the clarification Fireberd. I was wondering about when and how we'd get our product key. So upgrade to Win10 first then do a clean install? Is there any reason to do a clean install if everything works the way it should? What if I wanted to wait a few months or until next year to do a clean install? Assuming everything works  with just the upgrade that is...

The notification will happen in the same place as where you registered to be in the queue.

I think this queueing system is probably marketing faux, it's far more efficient for them to roll out regionally. All the information is there where you register an interest (the taskbar applet).

When ever a new operating system has been released, the general consensus among IT engineers is to always do a fresh install rather than upgrade.  That is so that there is little chance of artefacts from the previous operating system being present in the installation.  I think with an audio production machine with its requirements for strict timing, this would be even more important.

It is also recommended that a qualified IT engineer give you a hand with this as they are more likely to know a few tricks to make the transition go a smooth as possible and the end result be as trouble free as possible.

Personally, I would wait until Windows 10 has seen at least one service pack before installing on a production machine. If you're lucky enough to have a spare test machine (and the spare time) then that would be a good candidate for Windows 10.  Remember, you are permitted to run a copy of Sonar on two machines simultaneously, as long as you're only using one at any given time.

Also, if you are running a version of Windows 7 that is not eligible for the upgrade (Windows 7 Enterprise for instance) then the cost for Windows 10 Professional will be $US199.00.

Yup don't be in ANY hurry to upgrade!!! Most people should be able to handle the upgrade themselves. However you have to be crazy if you aren't using something like Acronis to backup before you upgrade.

Thanks Guys. I'm definitely waiting awhile before upgrading my main audio PC. I do have a 2nd PC I use for the internet and smaller audio projects. I have a Firewire interface, Cakewalk FA66. I might upgrade this machine to see how Win10 performs, but even then not right away.

hEARD YESTERDAY THAT AN .iso FROM mICROSOFT will be available to do re-installs on your machine whenever you want...That is very important to me because the best way to optimize and fix your PC is to do a re-install of a clean copy of the operating system so GAME ON 10! -s
 

I don't know if this has been posted yet, but you can download the ISO here to give it a test drive.
 
http://windows.microsoft.com/en-us/windows/preview-iso
 
Not sure if I want to bother with it or not.

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.
 
 

Unless you are able to format the drive, it won't be a clean install per se'. Windows will take the old OS and put it in a folder Windows old. Having a utility to write the drive to zeros would be optimum before a clean install.