I did upgrade to the 2.1 version but haven't tried any 3D acceleration yet. Does it seem to work ok?
Yeah it seems to work alright. I've only tested a few games, though.
It's not enabled by default though so you have to check "enable 3d acceleration" in the VM settings.
Also make sure you install the "Guest additions" otherwise it doesn't work
Right now it only supports opengl and Windows XP/Vista guest systems.
Sun plans on adding Direct3D and hopefully 3d acceleration under Linux guests soon.
It'd be cool if we could run compiz inside virtualbox.