If your going into computer graphics, then I guess a Mac well do "alright," just don't expect much when doing video editing... and if you do decide to do video editing on a mac, for crist shakes, don't use iMovie or iPro (or whatever), they're just pos.
I say get a PC, since you could fully upgrade it when needed.
Oh, and about the "mac has 128-bit processor while PCs only have 64-bit"... 64-bit processors are new... the only reason, that I could think of, that Macs has 128-bit processors is because the OS has to do the calucations and so it doesn't really use it to it's advange (don't you remember back in Win9x you have a 512-bit color setting? now we don't have that because it's just ugly)... PC processors does the calucations on the processor side, not the OS side, so it could take advange of the whole 64-bit part. (now that I mention it, did intel ever released there 64-bit processor yet? I haven't seen any info, then again I'm not really looking either).
Also, about stablty... The macs I've used in the past always crashes on me when trying to do something, never had a problem with my PC... then again, I take goooooood care of my PC, so it's only stable depending how good you keep care of your system.
NO ONE CAN TOUCH IT, ONLY ME, ME I SAY! *pets my cameras*