Just as a quick point of reference, they don't actually own the space. I do love them - I think they are an awesome company and expect they'll do well, but I just switched my entire company from Dropbox to Box. In short, Dropbox falls very short when it comes to "enterprisey" stuff like fine-grained permissions, etc.

They certainly _could_ own the space, but at the moment Box has a vastly superior enterprise offering.