I only know what I've read on Storage Review, and the WD Raptor (10K RPM, SATA, 8MB cache, fluid bearings -- it looks to be a pretty intimidating drive. It's very fast (its up in the higher SCSI range), and fairly quiet (I'd say in the lower third of all drives).
I don't know about that quiet part. There is pretty much no such thing as a "fairly quiet" 10K drive. In his review of the same drive on AnandTech, Anand noted that the Raptor was than the other drives he benched it against -- a SCSI Maxtor Atlas 10K IV and a Seagate Cheetah 10K.6! Couple that with AnandTech's infamous capacity for noise (like most in the performance/overclocking world) and it seems pretty acceptable that this drive is LOUD.
Personally, I'd wait for the Maxtor DM+9 SATA. Gotta find that silence/performance compromise, ya know? It might do it be a good one, and shouldn't be nearly as expensive as ye ole Raptor. HotHarware puts it as FASTER than the WD Caviar Special Edition, about 50% faster than the Cuda SATA (86% in one test), and also quiet. Quoth HotHardware: "We didn't compare the drive to every disk in our lab but the DiamondMax Plus 9 SATA drive, has quieter spindle and read head acoustics, than either the Western Digital SE or Barracuda V drives we tested."