When ATI introduced the Radeon 9800 series five years ago the company spend millions of dollars to get Half Life 2 bundled with the cards. Unfortunately, the game wasn't available yet at the time of launch so ATI had to include vouchers instead of the actual game.
FUD Zilla claims AMD will do the same thing with the Radeon HD 5870, the site heard these cards will include vouchers for DiRT 2, the first DirectX 11 game.
Radeon HD 5850 will also come with the coupon and once the game is out, you will be able to get your DirectX 11 game, again months after the release of Radeon 5870 / 5850. Still, this is better than nothing and Stalker 2 is also one of the soon to come DirectX 11 titles.