Even though the game is not a pre-order you can still get a FREE $10 Instant giftcard when ordering Dead Space 2 from Amazon.

$10 Credit Bonus Offer From Amazon
Order Dead Space 2 (Standard Edition) for PS3 and receive a $10 promotional credit toward the purchase of items shipped and sold by Amazon.com (certain exclusions apply, including Kindle books, MP3s, and video rentals and downloads). The promotional credit will be added directly to your Amazon.com account within two days after your order ships. Offer valid when shipped and sold by Amazon.com. Limit one per household. Amazon reserves the right to change or terminate this promotion at any time.