Variety reports he's nabbed the lead role in the film that will see writers Jonathan Goldstein and John Francis Daley ("Horrible Bosses," "Burt Wonderstone") also making their feature directorial debut. Details are thin right now about what the actual plot will entail, but Helms will be play Rusty Griswold, the son of Chevy Chase's Clark Griswold from the original series of films, who now has his own family and will experience comic misadventures all his own. So yeah, we suppose the message from New Line was: don't mess with the formula.
This news comes as a blow to Anthony Michael Hall, Jason Lively, Johnny Galecki and Ethan Embry who all played Rusty in the previous films. Sorry guys, no breakout role for you here reprising the character. As for Helms, he's good choice, even if the movie is pretty much going to be the same thing we've seen four times over already. Can Chevy be presuaded to make an appearance though? We doubt it. Last year he said he was writing his own "Vacation" movie that would take place on a cruise ship and return him to the lead role. Good luck with that.