The problem with GnuPG IMO is that real obvious use cases (healthcare) are out of bounds because it isn't FIPS certified and isn't usable by mortals. Having an implementation similar to OpenSSL with an API, and use case that attracted organization willing to sponsor FIPS validation would be a big step forward. Your doctor could securely send you test results. Your credit card company could send your bill directly.
Consider: The #1 solution for email encryption in hospitals/healthcare is Zix. This is sad -- their solution amounts to attempting to transmit an email via SSL, and falling back to sending you a link to a webpage. Cheesy.
Unfortunately, that's not the way things are, and usage of PGP are generally limited to security professionals, paranoids, and crypto geeks.