Well...If you have any plans on playing DX10 games comming down the pike in the next few years you won't have a choice. You'll get Vista or be SOL
Microsoft will not make DX10 available for XP OS...
Why should they?...they want you to spend money...right?
BTW...Vista is fine with SH4...Drivers are plentiful..and getting released fairly regularly, at least from Nvidia.
Creative has released a work-a-round for the sound problem with DirectSound in some games.
So..I'm really not sure what the beef is.