Sadly it seems this day was marred by genuine hooliganism and also overreaction to the simply foolish.
Excellent posts and comments on this at Precognitive, Saudi Jeans, and Saudiwoman's Blog.
NidalM, has done a post on his photoblog--In Pictures: The AlKhobar Riots. Well worth the look for the pictures, video, and context.
Meanwhile John Burgess of Crossroads Arabia has been updating regularly on KAUST from his perspective as an invited guest to the opening, and a former Saudi-based US diplomat. Nathan, an MSc student at KAUST, has created a blog to share his experiences there.
I join with Qusay of Precognitive in his wish: "Happy National Day Saudi Arabia, may every National Day be crowned with an achievement bigger and better than KAUST". And free from distracting hooliganism one might add!
Addendum: Some wonderful Saudi youth (1500 of them) personally gave framed written apologies and candy to the victims of the hooliganism, as Qusay of Precognitive reports here.