I think he'll be swithched between the two throughout the season but he will start on the wing due to Kuyt and Torres as said before. I have no doubt that he will get a chance to play striker but.
Wing because it will be too hard for him to play striker with the likes of Torres, Kuyt and Crouch competing with him.
I think he'll play as a winger at first but then in League Cup matches etc. he'll play as a striker, and then he'll get some chances up front in the EPL if he can prove himself as a scorer even if he's doing well on the wing.
I also think that if they were to play him frequently up-front, it wouldn't be the first season. You wouldn't have some happy campers.