No to Matthew Fox. Dude is not a bad actor but he's all wrong for Murdock, on par with Affleck for lack of inherent intensity. DD has a violent edge to him; we need an actor who can successfully convey that whip-smart, dangerous moodiness with his screen presence alone.
Meanwhile, Butler doesn't look the part and would probably have trouble inhabiting such an all-American role. Just don't see it.
Fassbender is the most Murdock-esque choice I can think of from the current generation of actors, but he's already Magneto and is now working on Assassin's Creed, so I don't see him dedicating himself to another geek role. A shame.