I think a sensible way to respond to the Imgur issue would be for theymos to ask LoyceV and joker_josue to come up with a CSV file of TalkImg "fallback" links (i.e. old Imgur link -> new TalkImg link), and then modify the image proxy to make use of that file (maybe by importing it into a SQLite database, or loading it into a hash table at startup, or something).
That way, everything (mostly; banning future Imgur links was a good move) stays the same (image proxy still shielding IP addresses, images stay Tor-friendly, etc.) and the problem gets fixed transparently (and Imgur can then set itself on fire, for all we care). Also lays the technical foundation for the next time something like this happens.
Just my 2 sats.
A CSV file or SQLite database won't do, it's gotta be a dedicated database server which can scale if Bitcointalk and consequentially the image proxy server is hammered with incoming requests.
Also if we are going to rely on TalkImg as a backbone, I still believe that the hosting costs should be subsidized by the forum treasury if required for network capacity to be met.