The only reason I trust the source of an email by its "from" address is because of the history of correspondence with that person from that address. Yes, if it is compromised, I may not realize it right away, or I may (see: phishing emails from virus/malware infestations), but by and large it works as advertised.
Same thing with usernames in forums. There's a certain cred that is eventually attached to a username over time.
If I use the same public key to represent myself in all my communication "for a while", then there's implicit trust that it's me there, for the same reasons.
Key revocation is admittedly not as simple, if I want to continue to maintain my "trust balance" somehow. What happens if I switch email addresses? "Hi guys, this is my new email address." What if I was compromised and someone else did that? (Well, how often does that happen in real life?)
Perhaps you could keep one key super secret (and offline) and sign all new day-to-day keys with it. I don't know.
What I'm saying is- Treat it like email. Forget trying to centralize who owns what key. Forget trying to exercise absolute control over trust in a given key. The key(s) I use "most of the time" is "me". If I need to revoke it, I will suffer some in the short term, but I will quickly build my cred back up by using a new one.
If it was more widespread then perhaps we could centralize SOME third-party signing. Say I could go to a bank and they could sign my key saying "this key definitely belongs to lectrick", and it would work because the bank's public key is known-trusted.