I was brought up in the seventies by a truly feminist boiler-suited mother who swallowed the whole guilt-trip inducing nurture-over-nature argument that mothers alone are responsible for the conditioning (and so underperformance/failures/whatever) of their offspring. As a result, my sister and I were denied dolls, dolls-houses or ANYTHING remotely pink. We were never allowed to wear skirts or dresses - Oh no, dungarees and trousers all the way for us in our brave new, self-determining, non-sexist world!
It wasn't so bad for me, since I was a bit of a 'tomboy' anyway, and actively wanted Meccano, Lego etc. My sister really suffered, though. She was a truly 'pink tutu' dolly sort of girl.
Well, until DS was born, I went along with my mum's way of thinking, but could see from day one of son's birth that it just DIDN'T apply. In my view they come out with personalities pretty well-formed, and DS was different from the girls and similar to most other boys. Now at 2.4 - predictably - he loves Thomas etc, and I do think that the sexes are characterised in different ways, but that it's a bit of a continuum and that generalisations can only be made with the huge reservation that individuals differ widely.
Also I don't like the whole 'tricksy girlies' angle. In general, girls have much stronger communication skills (a physiological strength I'm sure I've read - firmly proven) at an earlier age, and I think that they just operate on a deeper emotional level from the very start. I'd hate to think that this was seen as undesirable...
Haven't had a chance to read all of this long thread, so hope I haven't repeated others.