A lot of the comments are goofy or dismissive of the whole idea of Alex stepping down. But there are some serious suggestions, too. We get deep into the thread, though, before anybody mentions my own favorite, Mark Walberg.
Mark, of course, proved how well he could host a quizzer on GSN's late, lamented Russian Roulette. He has the combination of entertainment chops and intellectual heft to host the "thinking person's" show. Anybody who watched Mark play Lingo on the April Fools special knows this guy is no dummy and can easily handle the Jeopardy chores. He's done well on Antiques Roadshow, which is pitched at pretty much the same demo as the answer-and-question-fest.
But we'll have to wait and see if Alex has any intention of stepping down any time soon, or not so soon.