Eh, direct interpolation of population percentages simply does not work. It does not even work when talking about fish or rabbits, let alone humans. Higher fertility rates among Catholics should have made the US predominantly Catholic long ago. Didn't happen. The Catholic's had kids, they had kids who converted to protestantism and didn't want to have 8 kids of their own... If a population fails to become majority in < than 2 generations, it will assimilate. That is why English is still spoken in the US, although you would be very hard pressed to find anyone who's ancestors were primarily English. (The list of ancestory by percentage goes something like this: Germany, followed by Mexico, then some west African countries, then China, some eastern European countries, Japan,...Some other places...England)
Alot of the vagary in that list stems from the fact that many of the people in the US lied about their ancestry and/or were transported to the US against their will as slaves or indentured servants.
Also, there is a very heavy bias seeping through the cracks in those figures (Read: Evangelical Christians)
And even if Musilms do come to be the majority in some European nations, all the money is still in the hands of the "White Folk" who will panic and dramatically change immigration laws before they allow Muslim thought to dominate their culture. (Reactionary immigration laws in the US are in part responsible for the fact that English is still the only universally accept language there)
