Tribler is the only item mentioned that has P2P discovery, is the only one that is pushing decentralization to the last holdout preventing decentralized filesharing: trackers.

The other options mentioned here, RetroShare and VPN's, are about saying, fuck it, we give up, doing public p2p filesharing is impossible, we'll do it oldschool warez IRC channel style and build darknets for those that care to and know how to chase this stuff down into the deeper webs we're tunneling. There's -absolutely nothing- little new or progressive or decentralized or P2P about these solutions: they were done adequately when in 2003 Justin Frankel/AOL release WASTE (which itself was not supremely novel, just well done & usable), and before that IRC and FTP.

In other words, we still have no replacement for trackers (in the loose sense, given magnets), they make our p2p networks possible right now.