Will we ever be able to play all ps3 games on ps4 or will we always be limited to what PSNow allows
AFAIK we will only be able to use PSNow. The PS4 uses a different architecture (probably something else, I'm no expert), so no putting a PS3 disc in. That's how I understand it, I may be wrong though.
No, can't do. No PS3 games on PS4.
But as baracksyndel said, PSNow will allow you to STREAM games to your PS4. Requires a hella good internet connection without a bandwidth cap and you will most likely have to rebuy games (if you own any).
Will we ever be able to play all ps3 games on ps4 or will we always be limited to what PSNow allows