> File sharing copyright concerns, monitoring communications to catch bad guys and all that stuff is what's holding this back, not lack of a solution for connecting through NAT's.

Why? It's software transferring files between two parties, just like you can do with email and things like Skype and even AIM, and hell, even the service we're talking about. Is there precedent for the people who write such software having legal problems? I'm aware of cases like rapidshare and torrent sites, but for example, are the authors of bittorrent clients also targeted?

> I sometimes wonder how many people are under the impression that NAT's are a showstopper. This is simply not true.

Hmm, I'll admit I don't fully understand this, but back in my torrenting days, you always had to forward a port to be reachable. How do you get around that?