That's usually how it works... build a PC, good for a year or two, upgrade the video and RAM, good for maybe one more year, then build a whole new PC.
Well still cheaper then buying one. Though I suppose I should atleast hold out until the next Windows is stable. If XP showed us anything its that Vista will be glitchy for about two years after its release and we probably won't be able to use a lot of programs.
Knowing Microsoft we won't be able to use Firefox for a while.
Firefox actually runs pretty well in the RTM build.