What's funny is the fact that the "stock clocked" quad core is 400MHz slower and still keeps up with the E6850, which in games is about 1% slower than an E8400. When overclocked however it can beat the other CPU in almost every category. So if you're going stock vs stock then yeah the E6850/E8400 is the better choice.
And yeah the new Core i7 processor is going to fucking annihilate everything the benchmarks and overclocking results coming in on the early motherboards are absolutely insane. $1000 for a motherboard/CPU/RAM upgrade is too steep for me though, I'll wait half a year.
References:
http://en.expreview.com/2007/11/30/r...o-e8400.html/5