Looking to finally build a "real" gaming PC for the first time since college (jorbs are good, ya?), but wondering which route to pursue.  It basically comes down to purchasing middle-of-the-road parts or spending a little bit more for the next tier up that can be upgraded in the future.
 
For mobos/CPUs, the choice is between getting a solid i5 or the i7-920.  Because most games are more GPU-intensive, you don't need the triple-channel memory yet.  However, with the 6 core processors coming out for the X58 (eventually) it seems like there is a bit more longevity in an i7 over an i5.
 
For GPUs, the choice is between just getting a nVidia 265 or pulling out the extra cash for a 5780.  I'm pretty heavily leaning towards the 5780, but may wait for a few months to see what nVidia's new card looks like.
 
So should I go the upgrade every 1.5 years route?  Or pay a little extra for something I can milk more out of?

I would probably suggest the 1366 platform if you are upgrading now, my guess is that socket will have the longest lifespan (mostly guessing tbh though) but the graphics card market right now is very close to the new nvidia cards and we won't know how they will impact the market once they are out. I'm not sure what the best idea is graphics card wise but if I were to upgrade my CPU/Motherboard today I would definitely go for an i7-920 (if I had the money for one that is) 
 
And I'd also get some nice cooling for it (nothing crazy like water cooling, just a good air cooler) and overclock it, they can go up to and above 4 Ghz those CPU's and that gives you a pretty nice speed boost, that will make the computer's performance last quite a bit longer. And if I were to go for the i7-920 then I'd get 3x2 GB memory sticks for it :) 
 
edit: most important tbh is get a really nice quality PSU that will last you many upgrades, when you don't have to buy a new PSU/Chassi/DVD etc. it gets a helluvalot cheaper to upgrade your comp! 
edit2: let me just make myself clear.. no computer can actually be "future-proof" but they can last you a year or two longer or something like that (depending on how picky you are)