The one that has been posted on the Creative site since summer has very limited functionality. Luckily for all of us who have one of these cards, Creative released a new one, but it is not that easy to find it. For some reason this driver is hidden on the Asian site and is not listed among the European drivers. It works on Sound Blaster X-Fi XtremeMusic, Platinum, Fatal1ty or Elite Pro cards.
Just go here and download the one that works with Vista 32-bit RC1 and RC2 of just the 64 bit. We tried it on Vista 64-bit and works well, even the Fatal1ty font panel and the optical connection works, in stereo only, but it works.
The driver has some glitches and the only one listed is that some applications from your original X-Fi installation CD won't work and the 6.1 mode is not fully functional. ?