Roll the dice, try again.
Interview with Frank O Conner
New in Halo 4 are visual icons that point out which weapons are nearby (similar to Crysis 2 or Gears of War 3, only without the need to hold down a button to scan). This will be useful for newer players who haven't yet memorized where every gun spawns, but it might also serve a deeper purpose, too. "We mark the shotgun for a reason," says O'Connor. "There will be a very specific reason why the icon's there that you'll learn about later.
"You have the ability to choose from a wide arsenal of weapons and abilities that can be a part of your character's individual loadout," says Holmes. Right now, no one outside of 343 knows how much more ambitious this will be compared to what Reach offered.
Power weapons may not be on set timers
We're hearing that power weapons may not respawn in at set intervals, adding some unpredictability as to when rocket launchers, Spartan Lasers, and WMDs may reappear on the battlefield. The point of this is to make sure experienced players won't dominate matches by running timed circuits to grab all the best goodies.
Link here
Another video here
[Edited on 03.05.2012 9:35 AM PST]