Been keeping an eye on AeroFS. I don't see why syncing and storage should be mixed together (Dropbox)...
I just want them to support syncing existing folders rather than blessing a particular folder as the syncing one. Then we've got a nice zero-config p2p replacement for rsync.
I too really like the idea of aerofs. It was pretty buggy when I first tried it (years ago, at least it feels that way). In the meantime I found spideroak, which can sync whatever directories you tell it to sync, there's no special "spideroak" directory that you have to use. It also encrypts everything locally with my key that they have no access too before sending my data to their servers. It does have to use their servers though, it isn't p2p like aerofs.
I just want them to support syncing existing folders rather than blessing a particular folder as the syncing one. Then we've got a nice zero-config p2p replacement for rsync.