I am from the UAE. What the Saudi Government plans to do does not appears to be because they want to protect mobile operators revenues. It is rather because these two applications are quite popular among the Saudis and are difficult to monitor (unlike, say, Twitter). I have seen quite a few messages about corruption in the country being first spread through such applications.
As to those posters who immediately link this to Islam. Grow up please. This is just a dirty old patriarchy and such censorship has nothing to do with the religion.
Just a slight correction; I did not say the telecoms were "the" source of Fed income, but "a" source. I believe they contribute around 6% of Fed budget. Not that big a chunk, although nothing to sneeze at. As to the rest of your statement, lets just say that I respect your view and that we agree to differ.
Keep in mind that both Etisalat and Du give a large part of their profit to the Federal Government (who is a majority owner of both), so authorities have an interest in disallowing access to tools that may reduce their profit from phone companies. I am not saying that this is right or wrong. It is just a way to raise cash for the Federal Government which does not have many sources of income (oil income goes to the Emirates that own the oil fields, not to the Federal Government)
So what if UAE is trying to protect its youngsters from easily seeing smut content! I know some guys in the agency that controls web access in the UAE. They know about pirate pay, emule and all the other ways a moderately savvy adult can use to access "unsavory" content. Their logic is that "as long as it is not easy for kids to access that kind of content, we are doing our jobs". I am extremely OK with this.
Stop trying to impose your moral code on the rest of the world. The mature thing to do is to try to see thing from their perspective, not yours.
I am a local of UAE. Regardless of whether I agree with this or not, it should be noted in fairness that UAE's Government is asking RIM for access to the underlying data network similar to what RIM has already given the US and the UK Governments.