Modern Alternatives to PGP
blog.gtank.cc
blog.gtank.cc
The point is that OpenPGP is not valuable for the boring (but solid) cryptography but the fact that it is a widely used standard.
For the first the only progress I've seen is Keybase and their idea of a "social proof".
For the latter there is opmsg (https://github.com/stealth/opmsg) which uses ECDH or DH Kex for Perfect Forward Secrecy.
What if I want to send file securely and the receiver can grab it, say a week later because he's travelling on a country with no reliable internet connection?