Apple has released a new beta version with various advantages compared to the old one. iSight drivers, right-click support (through right Apple key) etc. as well as support for the Mac Pro and installation on any internal harddrive (still no FW support, though). Read more and download here
, users of an older version should definitely get this version and let the BootCamp Assistant burn a new drivers CD, so you can take advantage of the new features within Windows XP.