I wouldn't worry about PS4 games being unplayable at this point. Most are rather traditional core games. No motion control acrobatics. No esoteric cloud adventures. Just good old MP gaming + sharing.
PS4 is a lot easier to program than PS3 too ! And the western console developers are all familiar with GPU programming. If a shooter can hit RFOM level of fun, or an RPG can hit Demon's Souls level of intensity, I will be more than satisfied. Are the games fun ?
I would worry more about PS3 back-compat via Gaikai. In general, anything surrounding Gaikai needs more attention because it's new territory at this scale. It may look simple from the outside but it's not easy to pull off.
PS4 is a lot easier to program than PS3 too ! And the western console developers are all familiar with GPU programming. If a shooter can hit RFOM level of fun, or an RPG can hit Demon's Souls level of intensity, I will be more than satisfied. Are the games fun ?
I would worry more about PS3 back-compat via Gaikai. In general, anything surrounding Gaikai needs more attention because it's new territory at this scale. It may look simple from the outside but it's not easy to pull off.