"As our way of saying thanks for being part of this community, we're giving all qualifying Gold members two free Xbox 360 games each month for the rest of the year." reads the promotion's site. "Each specially selected, fan-favorite game will be available to download only for a limited time, so grab them before they're gone and keep them no matter what."
Update: Xbox's Major Nelson has since clarified Halo 3 and Assassin's Creed 2 aren't the two games due in July. This post has been amended to reflect that.