I'm testing 10 in VirtualBox as well - and just tried Firestorm x32 & x64, Singularity, and the SL Viewer. All of them say the load fails due to gfx driver not passing... WIll try VMWare player, but that means installing a new VM of 10 - that'll take a little time.
Also going to test with Linux Mint in a VM as well... :-)
Will keep you all posted.