I'd just like to address a few things:
What *kind* of rig are we considering? It's obvious there is no one rig that is the best at everything, so we should have several categories! If we are talking gaming then those dual Opteron rigs with 16 GB ECC ram aren't going to hold a candle to a nForce4 chipset with 1 GB ram in with a FX-55 even though they will run Maya much faster!
Also someone mentioned SCSI... I used to be a big SCSI fan (my last machine had 4 Cheetah X15s in RAID0 on a cached Mylex controller.) From my own tests, two Raptor WD740 drives in RAID0 absolutely SMOKE two Cheetah X15 drives in RAID0. And I dont have to cram 7 feet of LVD cable into my case anymore either!
To be fair, the Raptors are, for all intents and purposes, SCSI drives with an SATA interface...
I'm looking forward to see what SAS brings to the table though
