Yes, processors tend to age MUCH faster than games. The 4600 will play still be able to play much better if it had a fast CPU feeding it, such as a shiny 4.0 Ghz Prescott. Most video cards are hampered by strained CPUs. Video card longevity actually seams to last much longer these days, at least until new version of DirectX are being released. Prices are also skyrocketing WAY too high. I shudder to think about the system needed to play UT2003 fast with settings maxed.
Anyone that has the full game of UT2003, set every option in the detail option to "highest" and turn every eye candy opiton on there is. You'll get a REALLY GOOD LAUGH, trust me