Maybe for elves and humans. For dwarves I like the idea that there is no gender differentiation.
I feel myself that elves if anything do not need gender differentialisation. Them being androgyneous hippies and all.
Now remember that dwarves slave under a harsh and unforgiving god and similar conditions, much like worshipers of abrahamic religions. Tolkien even based his dwarves on jews and judaism which represent the archetype of the unforgiving god thing, which most of the organized stigmatization of females have sprung from(adam and eve anyone?).
Tolkien avoided opening the female dwarf can of worms since he felt that they'd become a subject of much controversy. His dwarven females were presumed to be kept locked-up inside the fortresses, which in itself kind of tells us enough. This whole thing about 'Female dwarves having beards' is a jab at salvaging this whole bit of dwarfdom, which tolkien certainly never made mention of.
Then again, Toady's chosen this interpretation, and thus i think we should go with it! Complete equality ftw! However it's easy to start to think in terms of gender, when they DO have gender, are called different things depending on gender, and one gender can have children.
Thus:
Reproduction
Slugs are hermaphrodites, having both female and male reproductive organs.
Once a slug has located a mate, they encircle each other and sperm is exchanged through their protruded genitalia. A few days later around 30 eggs are laid into a hole in the ground, or under the cover of objects such as fallen logs.
A commonly seen practice among many slugs is apophallation. The penis of these species is curled like a cork-screw and often becomes entangled in their mate's genitalia in the process of exchanging sperm. When all else fails, apophallation allows the slugs to separate themselves by one or both of the slugs chewing off the other's penis. Once its penis has been removed, a slug is still able to mate subsequently, but using only the female parts of its reproductive system.
I think this'd be interesting. Well except that chewing part, that's just gross.
I think it'd be a small thing to implement code-wise.