I wouldnt wait for pci-express..
1. It will take applications a while to be completely compatable with pci-x even after it comes out, which will be a long time all in all.
2.even when pci-x does come out, 16x will be a HUGE overkill to ANY game, you will not even feel the full power of 16x..
3. I garauntee the first pci-x cards to come out will NOT be under 500-600 dollars even at newegg prices because it will be new techonology and the prices will stay high for a while.
_P4 Northwood 2.8C Ghz HT
_Kingston 512 DDR400 Ram [2x 256]
_Awesome looking white plain case with cool green and red power/HD lights, and a newely acquired Intel P4 sticker!