I remember seeing and playing with a Celeborn hero card during a demo game at GenCon2010 last summer. If I recall correctly it allowed you to add a resource to a hero pool through an action... I don't recall exactly. But I see that Celeborn is not in the core set. Makes me wonder what happened to it or if it just got delayed to another expansion.

Hopefully he will appear in an adventure pack soon.

I am sure he will show up in the next cycle. After all the heroes have to deliver a message to Galadriel in the Shadows of Mirkwood cycle. I wouldn't be too surprised to some Lorien action in the next cycle or the first expansion set! (As a big fan of Lorien elves I also hope for that of course )