This is not a formal review, but quick thoughts immediately upon watching.
Up All Night pilot – good
It's on hulu right now... go for it.
I have never had a baby and do not remember much from my own infancy, so thus all of my experience with this kind of parenting comes from film and television — in this regard, Up All Night's premise is not exactly "fresh" (first time parents who yearn for their former craziness but also love their baby and would feel way too guilty if they still acted that way; also a working mom and a stay-at-home dad (which is not new either, and which I've seen a lot of lately on Parenthood)), but it's funny – there were times when I felt throwaway lines could have been a lot quippier (I didn't have to do any rewinding a la 30 Rock's joke-a-second pace (and Lorne Michaels exec produces UAN as well)), but there were enough really funny sequences to keep me watching (like Will Arnett's character not being able to find the cheese at the grocery store (why is there not more grocery store humor??), or the little snippet of deep conversation we hear him having with his new online gaming pal before Christina Applegate comes home, or the "brought to you by Nordic track"); Maya Rudolph's crazy diva boss character Ava, sort of the Jenna/Tracy of 30 Rock, I could see either being a consistently funny presence, or bringing scenes down, as my favourite bits were definitely little jokes with a more realistic bent ("I ate a personal pizza... from the freezer... I ate an entire twelve-inch pizza."; "At least you don't have to work." "Yeah, cos raising a human's not work at all."); a lot of Up All Night was funnier than it could have been due the actors having such a comedic presence (the drunken karaoke, particularly, could have been interminable, but was actually very amusing), and the pilot's conclusion masterfully avoided sappiness (by having Christina Applegate fill their "family" time with a prediction of her daughter's life after her father will inevitably die), but I don't really see much possibly story beyond episode-to-episode sitcom plots (about raising baby Amy, and taking care of diva Ava) — this could be really funny, once again, like 30 Rock, but if it doesn't work (or relies too much just on having funny actors and not such funny material — like the old lady in the grocery store, that really shouldn't have worked, except for Will Arnett, or the television talking to Christina Applegate,) or becomes too cartoonish and loses that realistic grounding, there's nothing except the actors to put it above a lot of shows on television right now