Gamespot has reason to believe that a Capcom artist accidently let the zombie out of the bag regarding Dead Rising 2 and the possiblity of a co-op mode. In a recent session at GDC 09 Izmeth Siddeek stated that Dead Rising 2 is going to have "the GREATEST number of characters in a videogame."
So how many is the greatest? According to the presentation somewhere in the neighborhood of 6,000 characters at once. Here's the exact quote:
"6,000" was mentioned as being the maximum number of on-screen characters when multiple players are involved.
Multiple players? That sounds like a co-op mode to me. Gamespot pressed Capcom for more info but obviously they declined to comment. We'll keep our chainsaws crossed on this one - it was a feature that was sorely missing from the original title.