Happily, I was wrong. Not that the movie was so much funnier than expected, but because it was so DIFFERENT than I expected. Granted, I was mildly amused throughout the film (Poehler's admonitions of wanting heavy drugs during childbirth actually made me laugh out loud. LOL if you will.) but on the whole the dynamic between the two women was much more interesting.
In many ways I felt this was more of a sweet "buddy" movie rather than a straight comedy. The kind of movie where two people are forced together, and gradually learn to appreciate each other. (Right now the only example that comes to mind is Turner and Hooch but I think you get the idea.) But it had never occurred to me that I've never seen a "buddy movie" involving two women. Suddenly the dynamic changes drastically and the movie manages to balance the natural compassion of these women with the growing frustration in their situation.
All in all, Fey and Poehler do the best they can with the material their given. There were several moments where any fan could imagine a retake with funnier delivery and reaction, so I have to assume that the director is somewhat to blame for the lack of belly-laughs.
Still, there are a few scenes that give you something to smile about later: Fey's boss (Steve Martin) rewarding her good work with 5 minutes of direct eye contact; Fey's mother (Holland Taylor) proclaiming that being 37 and single is an "alternative lifestyle"; and pretty much every scene with Greg Kinnear.