AGP 8X might be more usefull than you think for the ATI card. It might not double the actual throughput of the card (I don't think anything uses that much bandwidth), but newer games are getting to the limit and beyond, so it will help.
Serial ATA could be usefull as soon as March of next year.
And, even if they aren't usefull now, they give you upgrade posibilities. However, yes, I do think that the board will be the one that needs upgrades before Serial ATA will be required. But I wouldn't complain if I had them.
I'm still looking for a reason to upgrade my KT266A Board, and can't find one. There isn't enough of a difference in any of these boards to justify ripping my computer apart let alone spending the money. So I'll probably just sit on the computer for at least another year. By then, Serial ATA should have standardized, DX 9 cards should be cheep, and we'll know if Hammer will be worth it, and I can simply build a new system.
If ignorance is bliss, then why is everyone so miserable?