The PCI Express chipset wont be out in volume for 6 - 12 months, yes you might score one but dont count on it any time soon. What sort of computer do you want? Gaming rig? Server, Video editing machine, main production machine?
I have heard that the Intel boards, while not the fastest, are very stable. I suggest you check out Pricewatch.com , and maybe look at Ebay if you are willing to take the chance. There are a lot of Dell 400sc servers on EBAY and they are based on the Intel 875 MOBO chipset some going for as little as $300.00! Also whenever dealing with online companies you should check out
http://www.resellerratings.com/ .
The aiw ati 9800pro is supposed to be a KICK ASS card, but if you are really looking to upgrade to a PCI Express chipset board with in the year, you might consider going a little cheaper and saving your money for the new rig.