Also, new updates to the multiplayer modes have had light shed upon them.  Unlike previous games, ODST will have two discs for play.  One is the main campaign missions and the second is for multiplayer.  Whether you purchase a standard or limited edition version, both will include all previous downloadable maps, plus 3 new Mythic maps for use with either ODST or Halo 3.  The newest mode to be released is the Firefight mode.  Camparable to the Horde levels in Gears of Wars 2 and Nazi Zombies from World at War, Firefight allows for 4 player co-op to battle waves of enemies.  Unlike Horde though, enemies will not always come in the same strength size, so predicting future waves is not possible.   This will be the only difference in online play between ODST and Halo 3.  Firefight will have its own set of maps and skulls can be activated to either help or hurt your team.  Like Nazi zombies, their are an unlimited number of rounds, so teamwork is a must.  For more information about about either the ODST campaign or Firefight mode, see Bungie’s website or download from the Marketplace the free ODST videos.  And be sure to check back here as well