How long till obsolete?

Three months ago, my buddies and I put my pc together. I didn't get all of the top of the line hardware, but i got pretty good stuff, at a great price. My question is- how long do you think it will be till i need to really upgrade my pc? I primarily use it for internet gaming (raven shield, call of duty) and internet surfing. I was hoping this system would last me through the rest of college.(2 more years left!) any guestimates would be helpful. :good:
my rig is as follows. **i only paid 700 for everything inus the gfx card***

Asus p4p8x mobo
P4 Processor @ 3.0g
1Gb pc3200 memory (2 512 sticks kingston)
120gb hdd (western digital)
MSI Geforce Fx 5950 ultra
my case's box just said "scorpio" it has 4 fans and a 420w power supply.

I really wouldn't worry for another year, depending on how high of resolution you play at.

I think you have very good system which should last at least a year and maybe more.

i think the same

Yeah, it's a nice system. You'll be able to play most games without any problems for some time. However, you might find yourself upgrading if/when HalfLife2 and Doom3 ever come out to a Full DX9-compliant video card.