I would have to go with a lop mix - probably part Mini Lop. His face/head is too narrow for most of the lop breeds - that's why his ears stick out like they do, rather than lying flat against the side of his head. The only recognized lop breeds with narrow faces are the English Lop and its dwarfed, rex-coated counterpart, the Velveteen Lop. English Lops have very long, large ears; if this guy was even half English, he'd have much longer ears. Cute guy!
If you are guessing at his weight, I would actually put him on a scale. Rabbits can really throw a person on weight because of their freakishly lightweight bones! Might help someone identify his mix for you.