@ Soriku
Those 3 are currently by far the biggest announced titles, when they have been released new titles will have been announced. My guess is a Dragon Quest game, a Kingdom Hearts game and probably a PS3 console exclusive GTA V as the next big three after those are released.
I think Sony's experiments with new franchises worked pretty well overall, Resistance: Fall of Man, Motorstorm and Uncharted: Drake's Fortune are successful. The sequel Ratchet & Clank: Tools of Destruction and the new Heavenly Sword performed well enough. Sales wise Lair and Folklore were dissapointments, deserved to perform a little better.
Some yet unreleased exclusive games we know about for 2008/2009 release next to the big three: The Getaway 3, God of War 3, new Twisted Metal, new Jak & Daxter and/or Uncharted 2, new Team Ico game, new Ape Escape, new SOCOM, Killzone 2, Resistance 2, Motorstorm 2, new Tekken, etc.
I think antipation for such exclusive games will eventually push most PS2 fans to upgrade towards the PS3, this with pricedrops, slimline model as well as the big multi-platform game releases such as GTA IV, Resident Evil 5, new Star Wars, new Max Payne, new Alone in the Dark, new Tomb Raider, etc.
New efforts may bring in new people, new services like Home and PlayTV, new exclusive games like LittleBigPlanet, Eight Days, Heavy Rain, Infamous, White Knight Story, Afrika, Eyedentify, Haze, Wardevil, etc.
There's just so much coming we know about, I am certain there will be some surprises like Uncharted, Resistance, Motorstorm, etc were. IMO based on what we know the future is looking very healthy for the PS3.