The only reason I wouldn't buy the "extreme edition" is that in 1 year there will be new i7s that are 30-50% faster and cost 50% less. The shelf life for top-end CPUs is horribly short, unless you are writing it off as a business expense it usually is not a great bang for the buck.

Also keep in mind there are persistent rumors that Intel may release a new LGA pin config next year - i7 is 1366, they may release a 1066 or something slightly smaller. imo future proofing is never a good idea, I'd rather buy a new case/PS/mobo/memory/video card every 16-24 months (and sell/donate your old one) than try and jam new CPUs into old motherboards every 12 months. The $500 I'd save between a 920 and 940 right now I could use into buying a new i7 in 18 months.

The things I've read on OCP about the 920 i7 make me pretty happy, people are OCing it to near 4ghz on air and its performing great. Now of course the only real hardcore things I do on my PC are play 5 WoWs and watch blurays, both of which are fine on a core2duo and so the low end i7 will be fine for me. I probably will go that route over the q9550, since for just $400 more you get a CPU that is much better.