Sony has show off the PS4’s Remote Play capabilities in the past, but at the Brazil Game Show, Sony showed off Knack’s Remote Play features with a twist: second-screen co-op. Knack allows you to play couch co-op with a friend, with one player using the PS4 connected to a TV and the using a PS Vita.
http://www.youtube.com/watch?feature=player_embedded&v=uQkOklRLtz4
Each player has their own display (be it a TV or the PS Vita), so the game’s visuals aren’t scaled down to accommodate a split-screen view. The PS Vita will have a lower resolution than a HD TV, but at least each player has a full view of the game.
Remote Play will support all games, aside from those which require the use of the PS4 camera. And it’s available at the system level, so Developers don’t have to add it in manually, unless they want to support something like Knack’s couch co-op mode.