There are a lot of Islamist connections with OK, and have been for many years now.
Also, for a little more hysteria, I do recall that one of their recent ravings (either Osama or Zarkawi) included some reference to striking at the "American heartland."
Personally, I don't think there's anything wrong with speculating on these things. That's what forums like this are for. However, I can see good reasons - with all the games going on today - for the media not to be too ready to broadcast this all over the country. (Although I imagine law enforcement is certainly taking notice!)
One other thing about the Univ. of Oklahoma. They are historically one of the leading programs in the country in Petroleum Engineering. I assume they still are. For this reason, maybe others, there has always been a very large group of Middle Eastern males who attended the school.