I'm sure that insurers, especially car insurance companies, will find some way around the directive. There is bound to be a loophole which can be exploited, at least in the short term.
I can't imagine they'll whack a (potentially massive) premium on all ladies' car insurance, but they're hardly going to knock hundreds of pounds OFF every bloke's insurance policy, especially the youngsters and boy racers!
Will be interesting to see what happens, but I don't anticipate paying any less come renewal!