With the hardware jump being less of a leap then the SD to HD type thing last gen it was inevitable. Most of the early Ps4 / 720 games will have been developed for current gen systems and then 'ported up' with better graphics etc - basically just the PC version on higher settings. It's a double-edged sword, fewer exclusives will hurt it, but the Ps4 is going to have Assassin's Creed IV, Battlefield 4, Call of Duty, FIFA etc all before the end of 2013 at launch. These are behemoth franchises that typically sell around 10m a piece... compare that to Resistance and Motorstorm for the PS3's launch and then the whole 'PS3 has no games' thing and well... it's probably a better situation to be in.
PS4 / 720 exclusives will come in time as companies want to get maximum marketshare from the new consoles and as current gen software sales tail off. I'm sure first party stuff will be pushing that for sure, and I'd imagine EA, Activision, Ubisoft etc have stuff ready for E3.