The idea behind launch titles is that you can pad it with more obscure/lesser known/brand new IPs with the hope that gamers waiting on the games they KNOW they like will pick up to satiate a craving (Think RagOdy on Vita, filling the MH gap). You do want 1 or 2 well known IPs to be present though, preferrably the biggest attention grabbers.
-Uncharted is the equivalant to NIN's Mario. If they expect to draw people in it will be with this game.
-They will also want to tease what is possible in other genres, yet waiting to drop their bigger IPs to do so (Think Heavenly Sword as the precursor to GoW). Something very similar, but not quite. I heard that KZ dev's new IP is still another shooter so it could be that. MM, no idea what genre their next game will be but I see them putting that out before the next LBP.
-Also the PS4 should come with a game. Console Manufactures seem to forget gamers want to be able to work a system out the box, or have to pay for little else to get started playing. HOME is one thing but it should come with a game bundled. They seem to forget that helped the Wii a lot as well. This game should be family friendly, or simply a game that most people can play and immediately love.