The original "Father of the Bride" with Spencer Tracey is a really good comedy, the remake starring Steve Martin is a good sweet-natured, amiable enough comedy - and I don't really think a sequel was necessary at all. I mean the whole premise is basically the same - before George Banks (Martin) had to grasp the reality of his daughter being married, and now he has to come to grips with the fact that she's having a baby. A nice twist on this is that his wife (played by Diane Keaton) is ALSO pregnant, but nevertheless it's still (basically) the same as the first film in one form or another.
Thankfully it doesn't seem like a total cash-in (like so many sequels of this sort do) because it has a certain charm (as did the first film) and is still remarkably entertaining, all considered. But you can tell it was made solely because of the success of the first film - even Martin Short is back with another extended cameo as Franz the wedding manager. Of course you may be wondering why he's involved with a pregnancy, since his business is weddings. Here's a hint: more $$$ for the studio.
Martin is basically doing the same thing he did in the first film - the weary upper-class guy who feels overwhelmed by the state of things. Diane Keaton is still very sweet and likable as his wife. The rest of the cast (including Macaulay's little brother Kieran Culkin) range from OK to good. Martin Short, however, is yet again a stand-out and is very funny - he wasn't necessary for the plot but he is funny and a good addition to the movie regardless.
Overall I'd say this is one of those sequels that didn't need to be made, but could have been a lot worse. It's sweet, it's got some good lite-comedy moments, and in general it's just an enjoyable family movie that isn't trying to be anything other than simple entertainment -- which it is.
