According to MIT's Technology Review, Microsoft may soon have its own answer for 3d gaming that will not require glasses. The technology behind it has been around but has been too cpu intensive and costly in the past to be useable as a consumer product. The technology uses a display that is thinner at the top than at the bottom uses led's along the bottom edge that switch to create different images to different viewers or to create stereoscopic images by showing different images to the left and right eye. It also tracks eye movement. The tech can currently deliver 3d to two viewers at the same time regardless of where they are positioned and can deliver 2d video to up to 4 people (one video per person). The lens, developed by Microsoft's Applied Sciences Group is thin enough that it can be incorporated to standard LCD's. Read more about it here.