When starting the XFree86 server on an i810-based system, X won't start and I get the following error message: (EE) I810(0): I810DRIScreenInit failed (DRM version = 1.1.0, expected 1.0.x). Disabling DRI.
This will be completely fixed in XFree86-4.0.1-0.44. It's partly fixed in RC1.