Palin wouldn't be taken seriously over here at all. Politics is so totally different. Women in politics over here are still meant to be Thatcher

Strong, issue-driven, intelligent, not weak etc. We only have token female politicians around at the moment, they are all just fluff to show 'equality' and no one pays any attention to what they say.
Someone like Thatcher would probably still do really well at the moment, Tony Blair and New Labour destroyed everyone's trust in politcians, especially over Iraq. New Labour was all about spin, and presentation, hiding the issues and instead talking about vague stuff like "Change". The parallels with Obama are very strong actually. And he has to be very careful about promising too much. No one over here believes ANYTHING politicans say at the moment, on either side.
Tony Blair also messed up by not delivering on that change he promised, in a way that was perceivable to the public. Everyone is VERY disillusioned with Labour. And if someone turned up like Thatcher basically saying "This is bullshit", people would probably vote for it in droves, even if it was very right-wing. People are fed up of politicians trying to please everyone.
As far as American politics works though, I can see why McCain chose Palin as I explained above. I believe she is the big threat to Obama winning actually, and they are attacking her all wrong. She is meant to seem more like a member of the public, and the more they point out her flaws, the more people will rally behind her. Palin is basically a trap and a distraction, and could be highly effective. The best thing they could do probably, is ignore her.