In a P2P setup, there is no limit to having just one host.  You could have a heirarchial approach where there is one master host, with several hosts handling a subset of the clients.  Each subset could report to the host above them in the heirarchy.

32 players in warhawk is the best experience I had online so far, because you'll see a lot of people in the air and the rest on the ground, so if you want to win you must dominate the air then dominate the ground and all that happen lag free even when half the people are using lag switches. 32 players knife fight is even better but it's a lot tiering so I don't play a lot of those. I played online 6 matches off halo 3 online and 3 of them where really laggy so I was disappointed. Imo, 32 players matches in killzone and warhawk is far superior to 16 player in rainbow six vegas or graw2

well for the new server architecture there are no details to its specifics but most articles containing previews and what not state it, its the first statement in the details on their wiki :)
http://en.wikipedia.org/wiki/MAG_(video_game)

and in issue i think issue 193 of game informer whichever featured mag, stated that when the ps3 came out sony asked zipper to create a game massive in scale, which is the reason they weren't in charge of socom confrontation,

that might have somethign to do with it.

Not + just 50 players via Xbox live dedicated servers and 16 via p2p.

Who revived such an old thread?

Basically to wrap it all up:
PS3 uses servers primarily for their online games (no matchmaking system in PSN)
360 uses P2P primarily because it fits the matchmaking system and is better suited for small games
Both have advantages and disadvantages
Dedicated servers for all online games would be ideal, but expensive for lower player count games
There is no hardware limitation involved (both are possible of supporting many players). The 360 characters would look better, the PS3 characters could be slightly more numerous or more animated, but would look worse (R2 and MAG multiplayer graphics heavily degraded).

not only was this thread necro bumped, people are now trolling in it more than before, so it is now locked.