I downloaded Windows 8 onto a stand-a-lone PC and intended to use a Roland A-800 Pro controller with it for using vArranger. Two lessons learned:
1. First of all - there is no downgrade from Windows 8 so if you want to give it a try make sure you install it on a separate partition.

2. There are no midi drivers available yet for most of the midi equipment you might want to use with it. So, make sure you check your vendor first about Windows 8 support.

Deane