Hancock is not a quality movie. The story structure is terrible. There's nothing really going on. But you know what? It was a pretty entertaining 90 minutes. Yes, it plays more like a collection of funny scenes, most of the good parts of which were in the trailer but I still enjoyed watching Will Smith play a drunk, assholish superhero and many lulls in the film were glossed over by Charlize Theron looking her best since 2 Days in the Valley.
The film is basically an hour of character study and half our of plot. It's like watching the pilot of a TV series and then having the rest of the series condensed into a half hour at the end. So while I wouldn't recommend the film to everyone (especially those who already know they don't like Peter Berg's films), I had a good time and would tell anyone who's looking to kill 90 minutes this weekend that it's a nice trifle/diversion.