Despite the somewhat covert announcement (c'mon Sony, this should have been mentioned in your press conference), Journey promises "simple gameplay and accessible controls." Naturally it looks super pretty to boot. We're getting an ICO-esque vibe.
Interestingly, Journey is an online game, where players will encounter strangers throughout the game-world. It sounds like players will be able to affect the world for others too, which could be very ambitious.
It's due in 2011. Our interest's well and truly piqued. thatgamecompany are one of our favourite developers our there.