Flash Player 11 was officially released today. The single most anticipated feature for game devs are the GPU accelerated Stage3D APIs. But more so are the cool frame works built on top of them for 2d (Starling) and 3D (Proscenium) development. Check out the following links for details:
And just for good measure here's a video showcasing the capabilities of the new flash player:
Flash Player 11 & AIR 3 Features