I suppose who plays him depends on which 'side' of Beorn you wish to play up the most. If you're talking just about a big guy, then there are a lot to pick from - how about Clive Mantle who made a great Little John in Robin of Sherwood? Or are we talking about Beorn's menacing side? Ray Winstone could do both big and menacing without dumbing it down, seeing as Sean Bean's aready been used, or maybe Alfred Molina? Robert Carlyle does menacing better than anyone though, and with modern film techniques it doesn't matter that he's small. Or do we want to go for the wild side? In that case I go for David Thewlis. And finally, what about the shifty, shamanic side of Beorn? Do we want him to be 'intense'? In that case I'd go for John Malkovich or Joaquin Phoenix, even Ralph Fiennes if he could put on ten stone in film tricks and costume (actually, he'd make an excellent Thranduil so scratch that one
).