I've struggled with this for years. And I've always decided that having the greatest technology at launch isn't worth the extra money. Most of the time speed is all relative to what you're actually doing. My last two purchases have come at the end of the technology bubble, and I've ended up saving a substantial amount of money because of it. So my notebook has a Core Duo instead of a Core 2 Duo ... You're going to be paying a premium for new technology. That's not to say I've bought new technology on launch day. But my days of gloating are over. Unless there's something that you can see yourself using to get your money's worth, For example, the time period when Crysis was released and having a DX10 video card was something you wanted to take advantage of, there isn't really grounds to spend the extra money.
So you buy today, get a QX9300 (2.53 Ghz 12MB Cache, 1066MHz FSB) versus a i7 920 2.66GHz (8MB Cache)? Are you going to be banging your head against the wall because it isn't an i7?? Hell no.