Don't press for the "I'm committed" response - most likely she doesn't even know herself. She is confused and is trying to sort things out. Pressuring her to give you a black and white answer will result in the negative - I guarantee you. After all, what would you do if someone pushed you against the wall about something you weren't sure about?
Back off, let her say her piece and just be supportive of it.
So we're about to head into the battle of our lives, supposedly together (or at least parallel to each other), and I'm not allowed to ask her to make ANY commitment here???
That just seems wrong to me. I initiated this "bomb" with my e-mail of "I won't live in an affection-less marriage much longer," and now I'm the one having to tiptoe around everything. How did these tables get turned -- again -- on ME???