Bungie's Community Manager, Brian Jarrad, sat down with Joystiq to answer some lingering questions about the recent announcement of Halo 3: Recon. He explains that the game will have 4-player co-op in the campaign and that the game is built upon the Halo 3 engine, obviously refined to match up more with the passing of time from the last release.
The other big news is that the game will ship with new maps that can evidently be playable with a Halo 3 disc and will share space with the maps of those games. What that means I don't know, but it sounds pretty cool. Feel free to read the rest of the interview at the link below.
Source: Joystiq.com