Both ps3 and xbox360 still have much to catch up on it's platform. Many classic games are still in the process of remade to work on ps3 and xbox360. Wii will probably come up with something new due to it's incapability to cope with high end graphics and also piracy.

PS3 for sure wont be moving on to 4 in this year or even next year. They might announced 4 next year but it'll be 2-3yrs time to develope after announcement. They have been hammering on alot of firmware updates to deal with jailbreaks recently. If they wants to upgrade to 4, they might just stop dealing with jailbreak totally and leave it as it is like ps2.

Actually nowadays , most company wont take the initiative to release their product first. What they did is wait for the other side to release first and review heavily on their opponent's product. After that just provide a few features that other opponent doesnt have and release it . The rest will leave to their loyal fans to spread words for them and advertise their product. It's free , effortless and best of all save them money to advertise lol..