According to the Official Parallels Blog…
Installing Windows on a Mac is now Easier than Installing Windows on a PC!
According to the blog, the new Installation Assistant will automatically install Parallels Tools which makes switching between Mac OS X and Vista (as a Parallels Guest OS) much easier.
Time to fire up my copy and have it upgrade itself :-)
Happy to see some more competition to mature this important enterprise technology on the Mac, with VMware's Fusion for the Mac: http://www.tuaw.com/2006/11/03/vmwares-fusion-begins-private-beta/