Well I found an open-box version of the motherboard I'd been eyeing up on Newegg for $60 off retail, so I jumped on it while it was there. Thus, my hand is tipped.
New computing core will be:
Intel i7-920 Quad-core CPU (maybe 930, just released, will wait to see pricing)
Prolima MegaHalems Rev.B CPU cooler (Will run just about dead silent while overclocked.)
AsRock x58 Extreme motherboard
3x2gb G-Skill RAM DDR3-1600 (This may change if I find something on sale.)
nVidia 8800GT (from current system)
I'll be dropping all this into my existing desktop case, an Antec Sonata II.
Will probably just fire up XP (MAYBE trial of Win7) on it for now, waiting for Solid State drives to drop into reasonable range and then I'll move to a SSD with Win7.
For awhile I was considering going with the older style CPU socket and an i7-860 as it draws 40w less power under load. The problem is that socket's nearly dead and gone, and I'd like to have some room to upgrade this platform down the road.
Gah! Decisions! Second-guessing! Gah!