I enjoyed it. Jon Krasinski was very appealing as the gawky but nice Burt and Maya Rudolph was an excellent foil as his pregnant girlfriend, Verona. The plot involves their road trip to find a place to grow up with their baby and includes both some extreme humor (Maggie Gyllenhaal is particularly hilarious) and somewhat overdone drama. It's really a story about growing up and just what it means. The resolution is a bit pat, but it's also sweet.
By the way, this is very definitely an adult film. It's one of the best recent examples of what an R rating is for.