Heigl plays Alison Scott, a producer at E! who gets pegged to do on-camera work, goes out to celebrate, and promptly gets impregnated by Ben Stone (Seth Rogen), a Canadian schlub who, along with his buddies, hopes to make a fortune directing people (men) to the nude scenes in their favorite movies.
The unplanned pregnancy is a huge problem for both of them. A number of people tell them so, Scott's sister Debbie (Leslie Mann) and brother-in-law Pete (Paul Rudd) most loudly. Having been in a similar situation themselves a decade earlier, Debbie and Pete paint themselves as glimpses into the future for the young couple. While Debbie searches for understanding in her partner, Pete just looks for any emotional outlet he can find. Ben is offered varying degrees of help from his stoner roommates while poor Alison has no one to turn to but the basket case Debbie.
While Stone is the more interesting character and has more opportunity to develop, it's Heigl who crafts the more believable character. Though funny, Rogen's Ben has really only two speeds, stoner indignant and stoner sincere. Heigl uses far fewer colors to paint a far more nuanced picture. Rogen is ultimately the hero, though, because he gets the majority of yucks.
The film progresses from one set piece to the next, parading celebrity cameos (James Franco, Steve Carell, Ryan Seacrest), taking bong rips and showing frontal nudity. In these things it is incredibly funny. In mulling over the postmodern relationship, the story and cast are generally good, but the only people who really seem to get Apatow's vision are Heigl, Rogen and the director himself. It's enough, in the end, to make a really satisfying romantic comedy.
By my count Judd Apatow has now had two brilliant television shows flop and two films -- smart and funny, but hardly groundbreaking -- shoot to amazing success. The difference?
Like everything else, cursing and sex. Everything Apatow's ever done has been, to some degree, about boys, girls, slackers, overachievers, social awkwardness and drug use. All his films have that his TV series didn't is the cursing and the sex. The 40-Year-Old Virgin had a lot of the former and not much of the latter. Discussions, sure, but not much actual sex. Knocked Up has more of both, tons of pointless nudity and the absolute kicker: the geek fever dream that an oaf like Seth Rogan could land a girl like Katherine Heigl on nothing but wit alone.
What Apatow has learned, essentially, is to write for the smart kids (crushing married guy insights, copious film references) and direct to the dumb ones (physical comedy, weed sight gags, nudity) in such a way as to alienate neither. It's impressive. (Rated R)