The next big leap in video cards will use PCI Express technology.
You won't see this on the market until next year, and it means
buying both a new motherboard and video card.
AMD's Athlon64 should be out by the end of this year, same with the new Prescott core for the Pentium 4 (which may very well become Pentium 5). Not too sure about the Athlon64, but the new Pentium will debut at 3.4GHz.
Athlon64 is a 64bit processor, and the new Prescott core is rumoured to have 64bit adressing as well. Ooh la-la..
Of course, neither is in time for HL-2, if that's what you were getting at.