It wouldn't surprise me if this turned out similar to Lebowski. Not very liked by critics and that hurts its box office numbers but it becomes a cult classic. I personally think this will do well at the box office because of the names and this looks to be very funny. I think it will be their best comedy since Lebowski.
Movie critics generally don't know much about movies, but are very talented at whining about things that they could not produce for themselves. If you go by what they say, you'll miss some great movies and waste $5 (rock on, Galvetraz) on some awful ones.