So I am going to build a new system this summer, hopefully. It will be an i7 system and I am thinking with an ATI HD 4890(potentially CF down the road). My question is, should I wait for the HD 5000 series, will it be that much better? Would CF 4890's keep up in the new generation of gaming? Also, if I buy the 4890 now, and the x58 motherboard for the i7, would that still be good enough to run with the hd 58xx series card that comes out? Basically, is it worth the wait for the 5000 series?
There will always be new tech just around the corner. That is the way it works, if you wait for the 5000 series, the refresh will be out soon after etc. Basically, figure out what games you want to play maxxed out, then research what hardware you will need to do that with, then, pull the trigger. The only time I suggest people wait on hardware is when something that has an absurd price/performance ratio is on the verge of release like the 4770, or the 8800GT back in the day, but because you want bleeding edge performance, just splurge and don't look back.
Thats not a cheap system you are looking at so i would guess that the budget isnt a huge issue for you so just get whats good to go now and uograde as and when needed. Graphics cards keep a good resale price as long as they are not too old so you would probably get between 50 and 75% of the upgrade cost back by reselling anyway.