Looks like I upgraded to a full tower case just in time - I'm going to need it to house any of the new video cards that are due for release soon. Check out this offering from nVidia:
You might be happy about it's performance, but you probably wont be too happy about losing the 3 PCI slots adjacent to your AGP slot. Also, it draws 140 watts of power, so your PC will is going to need a 450Watt PSU to drive it. I'm not even going to think about how much power and noise this thing pumps out.. expect an offering of equal size from ATI soon (in the next week or so apparently)..