Steam opened pre-orders for 2K Marin's underwater shooter sequel BioShock 2 today. The upcoming first person shooter sequel from developer 2K Marin can now be purchased for 10 percent off its regular price before it's release on February 9. In addition, when you pre-order the game you can get the original BioShock from Irrational Games for free immediately! They also offer four-packs ($134.97) which are also eligible for the discount and come with four free copies of BioShock. For people who have friends, they can gift the extra copies to each other, thus getting the game for less than $34 each. All in all, it sounds like a good deal.