grumpyMike Resnick added some replies to my post about his article without actually answering my question, which is "What specific changes would you make to Worldcon to 'save' it?" But he's too busy working to answer that question, which didn't stop him from raising his original criticism and resorting to "the lurkers support me in e-mail."
If, as Crotchety suggests, the mega-shows are mainly about people who want their entertainment pre-digested and in easily consumable form, and conventions like Worldcon are mainly about people who are self-starters, then there's no way to "save" Worldcon without destroying it and getting rid of most of the existing membership, or at least relegating them to irrelevancy. There would be some irony, I suspect, as many of the existing "regulars" would go off and complain about how things are no good anymore, similar to so-called "Core Fandom's" complaints about how the Worldcon that they helped form doesn't revolve around them anymore.