Better specs, faster online, retro compatibility (and in the future the option to play old games in any device) through Cloud Gaming, a new touchpad, THE ABILITY TO PLAY GAMES AS YOU DOWNLOAD THEM, the PS4 has a 2nd chip only for background processing (like downloads in the background), the PS4 is always recording the last 15 min of your gameplay and you can share it without effort!
Also the PS4 will no longer have "setup" processes, like you know, you go turn on the PS3, and wait until it completely turns on, so you can start playing, well now that is over, you can press the power button of the PS4 at ANY time and the PS4 will enter a low-power state letting you go do other things, when you comeback, you just press the power button again and the system will restart JUST WHERE YOU LEFT IT, even in the middle of games.
More info about the PS4: http://blog.us.playstation.com/2013/02/20/playstation-meeting-2013-the-future-of-gaming-is-here-with-playstation-4/
Full info about the joystick: http://blog.us.playstation.com/2013/02/20/dualshock-4-revealed-pushing-the-boundaries-of-play/
Plus they said they will be supporting the Vita with the PS4 via Remote PLAY, THANK GOD! I bought a PS Vita and I was afraid that with the announcement of the PS4 they would announce a new handheld, but hell no, this is AWESOME!
Games: Killzone Shadow Fall, Infamous: Second Son, New Final Fantasy, Diablo 3 for PS4, Drive Club, a design software made by Media Molecule to use with Playstation Move, recently CD Projekt announced that The Witcher 3 will be in PS4 too, Watch Dogs, The Witness (a puzzle indie game made by the creator of Braid), among others I'm forgetting.
Trailers of games:
There is also the trailer of the game Deep Down (working title) by Capcom, which was uploaded to Sony's Channel but for some reason was made private short after, look a mirror at the end of this post below.
look for them here https://www.youtube.com/user/PlayStation
Sony announced today PS4 will NOT require constant internet connection, and will not put any barriers to SECOND HAND GAMING.
Plus Bungie the creators of Halo sided with Sony to make Destiny (though it's not exclusive, they will make exclusive content for PS4), Cliff Bleszinski left Epic Games to make his own games, I mean the 2 important exclusive franchises of Microsoft just got damaged, I mean: MICROSOFT IS IN A HARD SITUATION
SPECIAL MENTION: Deep Down (working title), a game by Capcom, that uses the new (also developed by them) Panta Rhei Engine, with IN MY OPINION the best graphics in REAL TIME yet.
Check this video:
And this is just 720p, Sony uploaded a 1080p version, but they made it Private now for some reason, luckily, I recorded it in 1080p (owned SONY!), so I will upload it later.