WARNING: THIS POST MAY CONTAIN SPOILERS!
I saw this at the weekend and surprise surprise... it was exactly like the original. With a few minor changes of course such as it was Stu's wedding this time, it was based in Thailand and instead of a baby they had a monkey.
Not that it made the movie any less enjoyable, it was just slightly disappointing. I know the writers didn't deviate from the original plot too much as the original was so successful but I think that if they had taken just a few more risks then it could have been even better.
So my advice would be to not expect too much from this story wise, especially if you've already seen the first one but it's still fun.