I think that inevitably petrol will become more and more expensive and less and less available, but I don't think it will ever get outlawed as such. The places where we'll be allowed to use it will also reduce as clean air zones become more widespread, but outside urban areas I don't think we'll see much restriction.
But for the next 10 or 15 years I don't think we'll see a big change, unless the climate goes completely mental and they bring in some pretty drastic laws to stop emissions.
