My spies say that BAe employees and dependants in Riyadh are restricted to their compounds unless absolutely necessary. Each BAe compound has an armoured vehicle outside. No camping or motor biking trips to the desert are allowed.
There's also a rumour of Pakistani troops being bought in to proyect the Royal family.
The Australian Dept. of Foreign Affairs has advised that all non-essential travel to Saudi Arabia should be cancelled. I also understand that the US government has issued a more strongly worded warning.
As for as I'm concerned, the writing was on the wall for Saudi Arabia ever since the September 11 attacks on the World Trade Centre.