everytime I try to think of why one system will win, I come up empty handed.
The 360 has it's lack of line-up and lack of appeal to non-US consumers, but good power for a decent price.
The PS3 is just so ****ing pricey, has similar thin line-up (it is new), but it is the leader of the last gen with all the bells and whistles you could ask for. Except there isn't a single blue-ray dvd out....
The Wii....well the name hurts a bit, many big titles missing launch, not nearly as powerful as the other systems, but it's got Zelda on launch, the controller, and will be signifigantly cheaper.
all three are basically a wash in terms of online support, imo, but the 360 is the only one that has proven anything so it has the edge.
I dunno, anyone who says they know is REALLY just guessing (this includes myself).