Shaun White Skateboarding isn't a terrible game, but it offers nothing to a genre with two well-established series covering all bases – the Tony Hawk series for arcade skating and the awesome Skate series for a very realistic, authentic approach.
Shaun White Skateboarding doesn't really offer any reason why it needed to be made; it doesn't do arcade skating as well as the earlier Tony Hawk games, and it certainly doesn't have enough realistic gameplay to compete with Skate.
Maybe rent this one if you're really curious, but I can't recommend buying it.