Are you planning on supporting more then just Dropbox?

I do nights/weekend IT support/systems design and setup for some small law practices and most of them are on Box. It's what has been recommended by the bar here in Massachusetts. Plus I've found it to fit a law office's workflow pretty well.

Before I could really evaluate this for a law office there would need to be a solid privacy policy in place as well as at least a blog post about data security.

I like that you're trying to move quick, but lawyers tend to move pretty slowly in adopting new technology. The concept is cool but as it stands now it'd be a hard sell.