I've only had a quick look this morning but the intention, I think, is to enable users to build up a private P2P network. I can think of a number of ways in which I could use this, particularly with friends/family who aren't tech-minded enough to use IRC.
Email just isn't an option for a lot of P2P stuff, even with Gmail, file size limits are pretty low and lots of file types are screened out.
It's more like the MSN shared folders idea - without the potential worry of transferring the stuff via and an MS app.
Obviously we're only talking about legal stuff here
