I think William Dafoe sounds good, although his voice and demeanor seem to me to be too...thin. His voice is a thin, cruel sounding voice (IE, Green Goblin in Spider-Man, Gill in Finding Nemo), whereas I look to Beorn to be a lumbering, boisterous fellow.
Stephen Fry, I know he's versatile, but I simply can't see him in that role. I haven't seen him in anything but
A Bit of Fry and Laurie and
Jeeves and Wooster, but still.
Auh-nuld and Chuck are both out.
I like the look of Bob Hoskins in the pictures.
One guy that jumps to my mind is Gordon Kennedy. He plays Little John in the latest BBC Robin Hood.
(The bearded fellow on the left)
He has that heavy-set thick face and the unkempt curly hair and an overall rugged look that I picture Beorn having.