I'm almost certain I read that this is a pseudo 256 player match. Technically you're all in the same game, but each team is divided into subteams which fight over separate areas of a larger map. This means you'll never see more than a quarter of that amount at once.
Again, seems to be another console exclusive game for the owners to wank themselves to death over. Just another cousin of the Halo series, Gears of War, Killzone. Little Big Planet and Resistance fall of man. Not necessarily bad games, just not as amazingly brilliant as most believe them to be.
I'd like to point out that the shear quantity of something (Players, vehicles, weapons, etc) doesn't really translate directly into fun, original gameplay. It sounds cool and is a decent technical feat, but small maps with 16-32 players are likely to be just as fun, if not more so than larger games. Less players not only generally means less dramatic requirements, it also gives you a chance to "bond" with the other players, make allies, engage in grudges, etc.
Perhaps MAG has a few other tricks up it's sleeve, I doubt it though. It'll take a lot more than just a large group of players to be successful.
