Have you heard the declarations that Tina Fey and Amy Poehler, former "SNL" buddies and now co-stars of "Baby Mama," are the new "Lucy and Ethel"?

It's an odd declaration, don't you think? After all,"Lucy and Ethel" were REALLY great together a grand total of, wait, one time.

Once.

It's not like "Lucy and Ethel" built a career out of funny. They didn't. In one setting on one television classic, "Lucy and Ethel" were funny.

So, from this declaration one would have to assume that Tina Fey and Amy Poehler have one perfect setting in which they will be comic legends.

"Baby Mama" ain't it.

It's hard not to watch "Baby Mama" without thinking "This should really work."

Despite a script from writer/director Michael McCullers (screenwriter, the "Austin Powers" films) that lets them down virtually every step of the way, Fey and Poehler do have a remarkable chemistry together and do turn "Baby Mama" into a solid, lightweight comedy destined for a longer life on home video than in theatres.

Fey is easily one of the most intelligent and funny actresses working in comedy today. Her role as 37-year-old corporate VP Kate Holbrook, who suddenly gets baby fever should capitalize on both her intelligence and girl next door qualities. The set-up is ripe with comic potential, both in Kate's professional world as a VP for Round Earth Natural Foods and its eccentric and earthy President Barry (a scene-stealing Steve Martin) and in her personal flirtations with a Jamba Juice-hating local health food store owner (Greg Kinnear).

When her "T-shaped" uterus reduces her chances of producing a child to one in a million and being single reduces her chances of adopting a child to even less, Kate aligns herself with a unique surrogacy program offered by the uncomfortably maternal Chaffee Bicknell (Sigourney Weaver) aided by the supposedly well screened surrogate Angie (Amy Poehler) and her trailer trash boyfriend Carl (Dax Shepard).

Have you ever watched a film and thought to yourself "This film is so close to greatness?"

That was my underlying feeling throughoug much of "Baby Mama." While "Baby Mama" certainly contains quite a few laughs, first time director McCullers never seems quite sure what he wants "Baby Mama" to be and, as a result, the comic set-ups feel disjointed and the characters float from contrivance to contrivance without any sense of purpose or direction.

Why does Kate suddenly want a baby so badly? Are we to assume that EVERY 37-year-old woman on the corporate fast track suddenly hits her late 30's and gets the baby urge?

While comedy sure doesn't always require plot exposition or multi-layered character development, "Baby Mama" does.

It's a rookie mistake by McCullers to assume that funny lines and sight gags are enough in a film about essential human emotions, relationships and desires with a cast capable of offering so much more.

Seriously, isn't Fey the actress you love to love?

Isn't Poehler absolutely stellar at playing characters who are both outrageously offensive yet surprisingly grounded?

"Baby Mama" can't fail, because the cast won't let it fail. Heck, the cast CAN'T let it fail. It's hard to imagine Fey ever being in a truly disastrous film, if nothing else she's a gifted enough writer to sniff out a cinematic dud before she commits to it. It's easy to see why Fey and the rest of the cast committed to "Baby Mama"...the potential is tremendous. Unfortunately, "Baby Mama" doesn't live up to its potential.

While McCullers falls short in his first directing effort, "Baby Mama" still is worth a watch largely owing to its stellar cast and their spot-on sense of what "Baby Mama" should be.

Fey plays it straight to Poehler's trailer park lunacy, and their chemistry helps to elevate "Baby Mama" as we grow invested in the plight of both women. While the ending is a predictable letdown, the journey nearly makes up for it.

While Shepard doesn't have to play more than his usual working class shmuck, he does elevate his game here surrounded by such a gifted cast. Likewise, Kinnear is well within his comfort zone here but still turns in a solid performance.

Sigourney Weaver wisely plays the constantly fertile Chaffee Bicknell straight, building up the laughs as her situation grows increasingly bizarre. Weaver's scenes offer the film's funniest one-liners, made even more funny by Weaver's constant self-assurance in the face of said one-liners.

Steve Martin, faux pony tail and all, brings to mind Tim Robbins' turn in "High Fidelity" as a completely yogified corporate head who gifts his employees with five minutes of eye contact for a job well done.

While it's hard not to watch "Baby Mama" without thinking what might've been, at its worst the film is still a notch above most comedies hitting the big screen these days. While McCuller's script feels underdeveloped and direction seemingly lacks the confidence to wrangle such a comically gifted cast, "Baby Mama" entertains on the strength of a cast that seemingly knows how to be funny even when the lines they are saying aren't funny.

While I'm not quite ready to declare Fey and Poehler the next "Lucy and Ethel," "Baby Mama" offers hope that contemporary comedy may have given birth to its next great comedy duo.