the reason i was wondering is because i heard the newer generations have some sort of upgrade capability that the older generation(s?) don't have.
are you sure? i've heard of different versions of the US PS2 but i thought the upgrade differences were in the Japanese models. usually, the only mods they'd be doing this early would be to make the anti-piracy tougher to crack.
anyway, it costs quite a bit to do these mods, even slight changes. i'm probably wrong but it seems inefficient to have 3 diff. models after being out for only 6 months.