Does Haiku use XOrg? XOrg is very buggy I have a lot of problems with it and I would be very disappointed if Haiku used XOrg.

No. It pretty much doesn't use anything you'd call a part of Linux (which I consider X.Org to be).

If you want a faster gui for Linux try E17. Nothing touches it.

"Gallium3D (wikipedia: Galium3D), the graphics driver architecture created by Tungsten Graphics designed to overhaul graphics drivers on Linux and other operating systems, has caused quite a stir lately.
Anyhow, a developer for the HaikuOS (the project designed to resurrect the BeOS operating system), has submitted a patch that adds Haiku support to Gallium3D. "

Gallium3D Support For Haiku Operating System