Some good friends of mine have announced full Linux support for their upcoming game,
Distance - A Next Generation Arcade Shooter. The team has already proven themselves with the spiritual prequel to the game, called Nitronic Rush, which has been the most popular student game released to date. The core team working on Distance are excellent folks: Kyle is super passionate about game development, Jason is one of the brightest engineers I've ever met, and Jordan is an extremely driven and talented developer. These are good people, working on a good game, and they're excited about being able to deliver a Linux version with Unity 4.
Unity 4's beta is out this week, and it has working Linux deployment support. The Distance folks have already tested it out and found out it's working great, hence their ability to commit to Linux support. Even if by some crazy happenstance you're not interested in Distance, at least send a thanks over to the Unity folks for getting Linux support working ahead of their own posted schedule.
Obviously if you're opposed to non-FLOSS gaming on Linux, this probably isn't news you care about.