Genesect DOES exist in the B/W coding; it's been found showing it to workers at the P2 Lab will get you two of its plates (the same two plates are from the same workers in the opposite game). However, the Pokémon does not seem to have a release scheduled as yet for the game while Keldeo and Meloetta releases are expected.
BTW, when you reply to a VM, visit the person's profile page. I see you replied to me but I knew nothing about it.
No worries, I was offering it for free. Obviously you have to trade something back, but it could have been a Lv.2 Lillipup and I wouldn't have cared; after all, I could quickly level a traded one to a high level while holding an Everstone and maintain the Pickup ability. I have other games and will someday be importing all of the non-Unova Pokémon into Unova; by doing such, I expect to be able to create a breeding center for anything wanted by someone (and I may trade Pokémon into White 2 to accomplish this as well).
So yeah, other than such a thing, this would have been a freebie, but it's unfortunate that you can't trade.