Warning: There is likely to be little new or interesting in this post, I just felt like piping up my thoughts.
I think that gender roles can be very useful in certain situations. Women, generally speaking (and this is at least partially biological in nature) are more nurturing and emotionally receptive. They have been hardwired by eons of evolution to be damned good at raising families, and those familial skills have applications in the real world. Women tend to make excellent psychologists and teachers, for example.
Men, generally speaking, tend to be analytical and curious. Men tend to make great scientists and mathematicians.
In addition, men are just flat-out stronger, on average. Thus, men are better suited for jobs like (as others have mentioned) policeman, fireman, construction worker, soldier, and so on. Both scientific (sorry, no cites available at the moment) and anecdotal evidence point to men and women gradually drifiting towards certain predictable interests.
I think that to actively discourage gender roles is to interfere with people making their own choices. If Little Tommy really wants that microscope for Xmas, I don’t think you should say, “Are you sure you don’t really want this Barbie, instead?” Let him have the microscope.
Now, of course, this isn’t to say that people should be pushed towards stereotypical interests. If Tommy wants the Barbie, let him have it. Similarly, I don’t think anyone should be prevented or discouraged from pursuing any career they choose… yet I also don’t think we should be launching large-scale campaigns to recruit a particular gender to a particular career. Just let things be, and things will naturally work themselves out. This will likely result in a lot of male policemen and a lot of women teachers. And that’s perfectly fine.
Now, one exception to this is that I don’t feel that women should be in the military in an active combat role. Not because there aren’t women who could kick ass and take names, but because having mixed male/female units creates very definite problems. Men are hardwired to protect women - again, evolution at work. As such, men are more likely to jeopardize a mission in order to save a female co-combatant than they are to save a male. Since this would, of course, lower the potential effectiveness of the unit, and since people’s lives are at stake here, I don’t think women should be allowed to be in any position where front-line combat is likely. Having women-specific and men-specific units would be prohibitively complicated (for reasons I won’t go into), and really isn’t worth the trouble. I have no problem with female officers outside of combat. They can be generals if they want, more power to them. Just not in combat.
Oh, with regards to bathrooms:
Keep them separated along biological lines. I agree that if a man really feels he needs to feel womanly, that’s his problem. However, if does a good job with his make-up, he can use the little girls’ room, and no one will be the wiser. 
Jeff