AMD has posted executables and videos for two new demos for the Radeon HD 5800 series. Both demos require Windows 7 (I guess that means that Vista support for DirectX11 isn’t quite here yet).
One of the demos show order-independent transparency; from the description it sounds like an A-buffer-like approach, which is interesting. The other shows a high-quality depth of field effect.
I believe the OIT demo uses a 2 passes approach. In the first pass each fragment is added to a per pixel linked list, while in the second pass fragments are sorted and composited (on a per pixel basis).