Doug, one of the cool players in my Wild Times D&D campaign, is really on a roll. First, in the comments to my new campaign proposal, he suggested tying the three subcampaigns together by making the three PC groups 'eternal champion' style lateral incarnations of each other. That's too cool. Now he's got a nifty idea for curing the Epic Rules Blues I've discussed in this earlier post. Doug suggests dropping the epic rules from Wizards and instead taking a page from Monte Cook's Arcana Evolved: stretch the campaign by adding standard progressions for levels 21 through 25. This would be a snap for some classes, like the fighter and sorcerer. Others, such as the monk, would need shiny new special abilities. I don't really need all the core classes statted out for this to work, just the ones that my players plan to take past 20th. Heck, with all the multiclassing shenanigans they pull, maybe no one will end up with 21 levels in any single class.
With four post-20th gestalt PCs, I bet we could still play Quicksilver Hourglass, the 30th level adventure published in Dungeon last year. That's been my big honkin' goal for this campaign for a long time.