Since up to now all the twins have been identical, I think seeing fraternal twins once in a while could be cool. I mean, the game already generates a combination of face/hair and clothes for a villager each time, and it also generates the fact that twins and triplets are born anyway. It doesn't take that much of a stretch of the imagination to see it simply putting together two different looks for the twins. \:\)
_________________________
And what if it makes you laugh now but you cry as you fall asleep?