For those who enjoyed The Hangover but wish it had more pensive reflections on mortality and Cialis jokes, CBS Films is prepping Last Vegas, a comedy about four older men throwing a Las Vegas bachelor party for the group's final unmarried holdout. Jon Turteltaub—of National Treasure and While You Were Sleeping—will utilize his talents for contrivance and sentiment on a story that so far has confirmed Michael Douglas as the soon-to-be-former bachelor and Robert De Niro as his "party-averse" pal (and former romantic rival) who reluctantly comes along and says cranky, modern-day De Niro things. Casting now turns to who will round out the quartet of withered former leads officially surrendering to their Sunshine Boys/Grumpy Old Men august years, with Vulture saying at least one role will likely go to Christopher Walken, while the other will likely go to the grim specter of death.