Arches, please keyword x11-drivers/xf86-video-nouveau-0.0.16_pre20110323 or mask the video_cards_nouveau flag in your profile. It is planned to remove the global mask for video_cards_nouveau on 2011-05-18. After that date, the mask will be moved to package.use.mask for x11-base/xorg-drivers if necessary.
Added to use.mask in profiles/arch/hppa.
Masked on arm/sh/sparc because no nvidia gfx can be used on those architectures Masked on alpha/ia64 until someone can test it
(In reply to comment #2) > Masked sparc because no nvidia gfx can be used That's definitely not true. SPARC is in the same category as alpha and ia64.
mips/x86-fbsd done by me. closing.