It's not that I don't believe he can't portray MacBeth and his rise and fall properly, I think PSH is a great actor. MacBeth has to be able to fight MacDuff, he has to be stately, he just doesn't look like the part.
And yes, he'd have to lose some weight to pull it off. I love PSH, but it all sounds strange, and besides, MacGuffin has not even replied back yet. And this is the JC thread.