Uncharted 3: Drake's Deception may have split-screen co-op.
Slow-motion shaky-cam footage of the game on YouTube shows what appears to be a fraction of a second screen encroaching upwards. You can make out the upper part of a HUD - the bit where a gun icon and ammo counter are.
It's dubious evidence to base confirmation on, but is strengthened by shop-chatter from last year that accidentally outed campaign co-op for 1-2 players.
Many of Uncharted's peers already offer campaign co-op, and with developer Naughty Dog pledging to "take on the big boys of the multiplayer genre", split-screen may be a necessary box to tick.