Sweet build! I just built my own i7-920 Hackintosh with similar components. Sold my old iMac and was on the verge of buying a Mac Pro but I didn't really think I was going to get enough value with the '09. No news about the update so I decided to try and build a hackintosh this time. Was expecting a battle but the whole thing was unbelievably easy. With SL and the right parts there is really no hacking included. Made an image of my retail-dvd, restored it on an USB stick, ran Kakewalk and pointed it at the stick and then just booted from it and installed SL the normal way. That's it! Everything updated through system update. Wouldn't believe it if I hadn't done it myself.
Here's my setup if anybody is interested (mobo + GPU are the deciding factors). Ignore the finnish and prices, just copy pasted from my receipt
Noctua NH-U12P SE2 -prosessorituuletin, LGA1366, L 36kk 1 65.90 €
Sandisk Cruzer Micro U3 16GB USB 2.0 -muisti, must 12kk 1 32.90 €
GigaByte GA-EX58-UD5 Emolevy Intel LGA1366-kantaan 36kk 1 244.90 €
Intel Core i7 920 2,66GHz -suoritin, boxed.Intelin 36kk 1 276.90 €
Lian Li PC-A20 E-ATX -tornikotelo, musta.Tyylikäs 12kk 1 336.90 €
Corsair TX850W TX-sarjan 850W ATX-virtalähde.Huipp 60kk 137.90 €
OCZ Gold Low Voltage Triple Channel 6GB Kit 3x2GB 12kk 1 182.90 €
Intel X25-M G2 80GB SATA SSD 2.5" (34nm) - SSD-kov 36kk 1 215.90 €
Gainward 8800GT 512MB Golden Sample (I already had this). Would have probably went with the fan-less Gigabyte 9800GT had I needed to buy one.
Only thing I'm not happy about is not buying a G5 case and sticking it in there. The Lian-li is sweet but not really close to real thing. This is something I may end up replacing.