1) I have owned a E8400 and now i have a i7 920. I played GTA IV with both CPU's, using the same HD4850 CF setup. You will have to take my word for it that i was not impressed by any major difference in FPS/gameplay! I recorded a "huge" difference of about 3FPS on average.
You can imagine, it doesn't mean shit when you are "in the action".
Funny thing is, one of the reasons i bought the i7 920 is because everyone "so calld experts" sweared that a dualcore was crap for GTA IV and a quadcore was way to go. Well, i put their words to the test and it ended up in a big disappointed. Well, as far as GTA IV performance goes, that is. Encoding is another hobby, so it suits well in the end.
2. Future games will mostly be ports from consolole games. In many cases, not the best ports also. Why worry so much about cpu performance tomorrow, as you can see that a three, four year old E8400 still manage to be there,often right in the top of the charts.
I am glad we Tom ain't showing as useless 800x600 low settings results, to show a "theoraticle potential of cpu power", while in the end, in practice; you are gonna swear your pc if it doesn't handle 2 or 4X AA at 1920x1200 for example, with HIGH settings.
Really people, you're lookin at it the wrong way. Tom's spot on here, my congratulations!