I think it'd be cool to have random cabal, fallen, vex, etc. ships that would appear while we're out in space. When a player finds one of these ships he/she is presented with either raiding the ship or avoiding it entirely. The ships would range in size from the "Forward Unto Dawn" up to the bigger "Pillar of Autumn"-esque ships (2 halo ships). Heck, if bungie could go bigger why not put in ships the size of the "USG Ishimura" (Dead Space) To get a sort of feel on how these raids would go down, look to the halo reach mission "long night of solice" OR that one map from Starwars Battlefront 2 (the one where each team has a home base ship). The player(s) would first need to board the ships without getting hit by flak from the enemy ship's turrets. After docking, the player(s) could roam around the ship trying to find weapons, items, etc.