Hi.. 
 
I need to upgrade to Windows 8, because I need to run the Windows 8 Phone SDK.   I actually get a nice discount on Win8 Pro, so I am going with that.
 
However, "what will happen?"   Is my machine going to be totally reformatted?   So I will basically need to spend...  PITA 2 weeks?  Reinstalling all my music soft?  I take it, I should probably back up every single document, or file that I have created to the cloud, beofre I do this?
 
Thoughts?  thanks...

Went without a hitch here.
 
The install program analyses your hardware and software and advises on any incompatabilities.
In my case only SoundForge was flagged up so I updated to the latest version and everything was fine.

I did an upgrade from Win 7 to Win 8, on a "backup" PC and don't recall having any problems.  However, it has since been completely rebuilt due to a motherboard failure and a hard drive failure.
 
You could repost the question on the Windows 8 forum and see what the Win 8 "experts" say.   http://www.eightforums.com/

Is the navigation (mouse/keyboard) and general use-age on Win8 better than Win7 with X2? (I don't have either, but deciding on which one to get......I'm not planning on using touch screen (yet)). 

I don't notice any difference between Win 7 64bit and Win 8 64bit.  Sonar X2, at least what all I've used, works identical on my dual boot system.

It will work...

Sonar will work on dual boot, if you upgrade it to windows i don't think that any problem will occur, i am suggesting you that go for it cheeerss....

so when we say upgrade does that mean actually upgrading or a clean install wiping off the drive and re installing every piece of stuff we've piled up for the last four years?
:)
I'd really love it if the upgrade feature actually worked...
WSS

"Upgrade" can have serveral meanings.  Upgrade can mean a new PC and new OS, or merely mean moving from one OS to another (and a clean install) or it can refer to and in place upgrade of an existing OS to a new OS. 
 
I've done both a clean install of Win 8 and an in place upgrade from Win 7 to Win 8.  I didn't notice any difference in either system.  Years ago an in place upgrade of an OS from one to another was a disaster and a "clean" install (reformat the hard drive and install new) was the only real option.  Although a clean install is still best, with Win 7 and Win 8 an upgrade from an older OS to a new is not the disaster it used to be. 
 

Linear Phase
I need to upgrade to Windows 8, because I need to run the Windows 8 Phone SDK.   I actually get a nice discount on Win8 Pro, so I am going with that.
 
However, "what will happen?"   Is my machine going to be totally reformatted?   So I will basically need to spend...  PITA 2 weeks?  Reinstalling all my music soft?  I take it, I should probably back up every single document, or file that I have created to the cloud, beofre I do this?

You can do an upgrade install of Win8, but... it opens the door for potential problems.
If you want to be sure you're starting with a rock-solid foundation, that means performing a clean install of Win8x64.
Backup all data (docs/pics/etc) prior to the install...