I think all three of them have the potential to be first team regulars here at RFC.
I believe Karacan has all the attributes. But I think Karacan will need about 2 or 3 years of experience in the first team before he matures into a very good Central Midfield player. (In the same way that Sidwell and Harper needed to mature and gain experience before they became really effective. Sidwell gained experience at Brentford and Brighton and took about a year to become really good for us as well. Harper wasn't brilliant straight away. He needed a few years before he became a Premier class Centre Midfield player)
I also think Pearce has all the attributes to be a top top centre half. But he too will need a good couple of years of first team Championship football either with Reading or out on loan before he matures in to a really good centre back for us. (In much the same way Adie Williams needed about 2 or 3 years before he suddenly became a class centre back) With the first two, they just need experience.
james henry, I'm not so sure about. 1 game isn't really enough to judge the lad on. He needs to make a number of starts and he clearly has alot to learn. There were alot of things that he was doing wrong against Blackpool in my opinion. It doesn't mean that he can't become a really good right winger, but he has alot he needs to work on before he becomes effective enough and able to make a difference in a big game. Rosenior needs to talk to him more and point out his errors. And henry needs to listen to the experienced pros around him and make the runs down the wing that he wasn't making against Blackpool.