Black 2 and White 2 were recently released worldwide, and with them comes some new breeding mechanics that you should probably be aware of. This information comes from Serebii.
Nature Breeding:
Before, if a Pokemon held an Everstone, its Nature had a 50% chance of being passed down to the Egg. Now in B2/W2, it is a 100% chance of it being passed down. So breeding for Nature's has been made easier. If both parents hold the Everstone, the chance is 50% for either parent's Nature.
Ability Breeding:
Before, a Pokemon had a 50% chance of receiving either of its Abilities(or of course 100% if it can only have one Ability). Now, they have given the female parent a bigger role, that is, whatever Ability the mother has, the Egg has an 80% chance of having that Ability(or whatever Ability the Egg would have that would become that Ability, the example Serebii gives is a Venonat's Compound Eyes Ability becoming Tinted Lens as a Venomoth.). With a Ditto, the chance goes back to 50% for both.
As for Dream World Abilities, the mother must have the DW Ability, and if it does, the Egg has a 60% chance of hatching with that Ability, and 20% for each of the other two.
Nurseries:
This is a new mechanic, that unlocks after you beat the Elite Four and you get your Join Avenue up to level 15. You will be able to purchase items that decrease the hatching time of the Eggs in your party.
http://serebii.net/black2white2/breed.shtml
Brock Out.
