Charlyne Yi, Chris O'Dowd part of four new additions to Judd Apatow's Knocked Up spinoff

Judd Apatow's spin off of Knocked Up is rounding into shape. Titled This is Forty, the film is a first for Apatow in that he's revisiting two of his most popular characters, that of Debbie(Leslie Mann) and Pete(Paul Rudd), the troubled married couple who seemed to be getting their act together at the end of the story. But this isn't really a sequel, it's just a "continuation", which takes place a few years after Knocked Up concludes. While there's still no word about Seth Rogen or Katherine Heigl reprising their roles(doubtful), Rudd and Mann aren't the only ones who'll be coming back for seconds.

Variety reports that Apatow has added four more to the cast of the film: Charlyne Yi(Paper Heart); Chris O'Dowd(Bridesmaids); Lena Dunham(Tiny Furniture); and Wyatt Russell(Cowboys & Aliens). The returnee is Yi, who had a small role as Jodi, a stoner buddy of Rogen's character. O'Dowd has recently become a hot commodity after playing the love interest to Kristen Wiig's character in Bridesmaids. He also appeared as the villain in Gulliver's Travels, not that anybody should care about that. Dunham has been an Apatow fave ever since she wrote, directed, and starred in the popular(and overrated) indie comedy, Tiny Furniture. She's now working with Apatow on the upcoming HBO series, Girls. In the film, she and O'Dowd will work for Pete's new record label. As for Russell, he's relatively new to the scene, but when your parents are Goldie Hawn and Kurt Russell that's probably not a big deal. He'll be playing a hockey player. Not sure how that fits in to the story.

Megan Fox and Albert Brooks are already confirmed. He'll play Pete's dad, while Fox will likely be some sort of temptress who throws his marriage into jeopardy. Just a guess.  Shooting begins later this summer, with a December 21st 2012 release.