I still betting on Hook, or maybe the guy who is in the mirror.
But the “becomes part of the show very quickly” pretty much rules out Hook (as does all the CaptainSwan stuff we know they are going to do). Hook is already a part of the show, he doesn’t need to become part of it. Sydney I also doubt very much as Giancarlo is only in one episode before he is going to be due back at NBC for “Revolution.” He can’t really be a love interest because he won’t be appearing on OUAT; maybe once if NBC is nice and his schedule permits, but not enough for him to be a legit romance partner for Regina.
I think they are going to be playing Pan around 17/18. Both of them are cunning. Hmm, I am not going to give up on my Rumple/PP brother thing. Unless we find out how long PP has been around.
Robbie Kay is 17 (18 in Sept I think) so his physical appearance will be about 17 or 18. However, his actual age….well we know he is as old as Rumple so about 300 (grumbles something about the t-word) but if he “has game” as the article suggests that I think it’s very likely that Peter Pan is actually older than Rumple.