Flash 3D
Flash natively has always been 2D. Various methods have been developed to simulate 3D or import it from other tools such as 3D Studio Max. Aswell, libraries have been writen to create 3D, such as papervision3D.
Lee Brimelow, who had a great and funny demo session at the Adobe Air Bus Tour, interviewed Justin Everett-Church about the new flash player 3D support. Looks like a good start to a long standing 3D dream. You can view the interview here.