Cool. I've haven't seen of his stuff in ages, so I can't remember what I think of him as an actor, but he'd be pretty prestigious hire for Marvel if they can get him.
Go watch "Her", please.
A brilliant performance and an equally brilliant SF movie on top of it.
Phoenix might not be visually Dr. Strange (RDJ would be the spitting image but he was also the spitting image of Tony Stark, both characters have visual similarities) but he's a top of the line actor and it seems Marvel movies attract top talent which is awesome in itself (a decade or two ago A listers wouldn't be caught dead in a superhero movie).