I know most people want Jason Statham to be Butler, but whenever I read about Butler in the books I've always imagined a bald Liam Neeson. After his roles in Taken, The A-Team, Batman Begins, Michael Collins (my favorite), and his new movie coming out called Unknown, I think he may be able to look tough enough for the part, but still have the softness to enjoy reading romantic novels! (just like Butler)
I know he's probably 10 yrs too old, but he has the build. He is really tall! (And Butler ages prematurely for a while anyway). Liam's all Irish, but just maybe he could pass as Eurasian???
I would also love to see mostly unknown Irish/European actors for other various roles. I think that just like the Original Star Wars & Harry Potter, it's nice to give parts to new actors we've never seen before. I think it keeps the story fresh and exciting.