Flash is getting a hardware-accelerated 3D in an upcoming version. Code name is "Molehill", and it's basically a new API that is backed by OpenGL or D3D depending on the platform.
http://www.adobe.com/newsletters/edge/january2011/articles/article1/index.html
This means that anything you wanted to do with Quake in flash could now be done with hardware-accelerated graphics. Picture Fitzquake or DirectQ quality graphics and framerate in flash.
Porting could begin now with the beta code available. I haven't touched it yet because it already takes like 10 different package installs just to compile the current flash quake (cygwin, flashdevelop, alchemy, flex, java, etc...) and I haven't had much time to bother with it.