Yes. This has been covered fairly extensively, but I don't' have the time to go back and find it, in this incredibly long thread, so I'll try to hit the highlights for you.
This part of the theology is the part where mainstream LDS and Fundamdamental LDS(FLDS) merge in their teachings. Back when
Warren Jeffs was on the lam, and in the news, many LDS were really offended by him, and the practiced polygamy. They made a point to explain that mainstream LDS did not condone the practice, and that FLDS was in no way associated with the LDS.
That's true in practice, but in theory, mainstream LDS does still believe in polygamy, but it's only in the afterlife. Their view is that before we were born, we all lived in what they call the Pre-Existence. We were spirit babies of our Heavenly Mother and Heavenly Father. Only the very best, most righteous Mormons make it to this level (this is where you're a God and Goddess of your own worlds), and the kicker is that if you're a very good Mormon woman, your reward will be to be one of many Heavenly Mothers married to the same Heavenly Father and popping out spirit babies for all eternity. Really makes you want to be a good Mormon woman, doesn't it?
ETA: I remember my mother being very close to another woman in the church--one of those situations where you just meet someone but you feel like you've known them forever. For most of us, this is a pleasant, but normal experience, and we're glad we met someone we feel so close to, and leave it at that. I recall this woman and my mother having convinced themselves that the reason they felt so close to one another from the first time they met was because they were born of the same Heavenly Mother. So, yeah.

Pitiful.