On the surface, Baby Mama looks like a no-brainer of a comedy. The trailers pointed to a slam dunk of a fun movie, not aspiring to greatness, but sure to provide a steady stream of laughs and chuckles as delivered by a former Saturday Night Live alum teaming with a current cast member. So, did those trailers point us all in the right direction?

Well, sort of. While it did provide some sporadic laughs, it turns out that most of the big laughs were in the trailer. There is also the problem of potential — there is more that exists in the concept than what appears in the final product. I am sure that most of you know about concept potential — it refers to an idea that has many directions to explore and a level of depth that could be attained, yet isn't. Baby Mama seems to be content to wallow in mediocrity. Fortunately, this mediocrity is still worth watching, at least until the story intrudes on the fun.

Tina Fey stars as Kate Holbrook, a career-minded executive for a chain of health food stores. As she gets older she discovers that there's something missing in her life. Despite her protestations to the contrary, Kate feels a deep desire to have child, a desire that isn't going away. Kate gives into those desires and does everything she can to become pregnant; unfortunately, it is not to be. Not giving up, Kate turns to Chaffee Bicknell (Sigourney Weaver), the head of a company specializing in placing potential mothers with surrogates. Enter Angie Ostrowiski (Amy Poehler), a white trash woman with an even trashier husband, Carl (Dax Shepard).

Angie agrees to be Kate's surrogate and the process moves forward. However, a wrench gets thrown into the gears when Angie and Carl have a falling out and she shows up on Kate's doorstep. What follows is an Odd Couple-styled relationship that is funny until the plot comes into focus.

There are a few threads that weave together forming the ratty tapestry supporting the comedy. On one hand, there is Kate at work, looking for a new location for a store, and in the process falling into a relationship with a local shop owner specializing in fruit smoothies (Greg Kinnear). This involves a funny-for-a-minute supporting performance from Steve Martin as the new-agey company head. Her work responsibilities are balanced by Angie and the little bundle that she carries.

Now, the plot does bring with it some surprises. Well, not really, but why would I want to rob you of the potential joy to be had in uncovering all of Baby Mama's secrets? Okay, perhaps that was a little overboard, but there are still some interesting directions taken as the attempt to fuse comedy and heart with a story that tries to force that round peg into the square hole.