I am looking forward to Hornet[0]. The authors haven't put a PoC out yet. It is described decently in a recent mailing list post[1] (and impl[2]) on a BitCoin decentralizing project. A quality project might take the speed of the Hornet protocol, the tor hidden services approach, remove the exit node concept, make everyone a relay, and incentivize bandwidth sharing.
Sadly, I don't think we will witness a working implementation of Hornet anytime soon. Hornet was designed to be implemented at the core Internet infrastructure in order to operate at the network level. It is practically -impossible- to achieve this level of migration (remember IPv6). Moreover, it requires the deployment of a PKI on an unprecedented scale, which may or may not be secure. However, it's true that some ideas might be extracted and used in other future projects.
0 - http://arxiv.org/pdf/1507.05724v1.pdf 1 - http://lists.linuxfoundation.org/pipermail/lightning-dev/201... 2 - https://github.com/LightningNetwork/lightning-onion