We're working pretty hard on Keybase. For the last year it was just 2 of us (me and https://keybase.io/max) , but some amazing people just joined the cause and we're building a much better service. Our Go client, for example, is almost on feature parity with the old Node reference client, and we've started working on a nice OSX GUI.
A lot has been written about PGP and its shortcomings, and we agree with pretty much all the points: client integration problems, usability, the WoT just sucking, key management, revocations. So far at Keybase we've attacking one of the most important problems with PKI in general, not just PGP: getting the right key for someone. But it's really only one piece.
I don't want to (yet!) give away too much of what we hope to launch later this year, but there's nothing about Keybase that's specific to PGP. Or chat - which people seem to get hung up on. We think we're in a very good position to release open source software that makes people's lives more secure and more convenient. Everything from financial transactions, chats, and releasing public software should be easy with a PKI. It's just not working yet.