Jack Shafer brings up a good point in his Slate article The New Power Generation about how to tell when the boomers have jumped the shark.
While Shafer brings up the mainstreaming of catch phrases from the Simpsons as possibly signaling the fade out of the boomers, I like to think that a South Park-esque reference in the New York Times, preferably in the book review section (example:"Post-modernism blows!") will provide the all encompassing sign that the boomer era is over.
Which brings up another observation: the generational shift of power in the 60s and 70s was a brutal ideological blitzkrieg that took no prisoners and laid waste to the cultural heartland of American small towns and suburbs. The current interest in "The Greatest Generation," is not so much a way of making guilt driven, fawning, amends, but rather a careful and calculated move by the most self absorbed generation to set the tone for their treatment by the post-boomers.
What will happen, though, is that the Xers and Yers will revile aging boomers for draining scarce pension funds and medical services. It's happening already in the sitcoms and movies: boomers are stereotyped as having been sexual libertines in their youth, addicts and spendthrifts in their adult years, and perpetually lost adolescents in their middle years. Perhaps the character of Frazier's father, Martin, will go down in pop culture history as having been the first indication that the boomers had lost their hold on the popular imagination in comparison to generation before.