In Xorg 7.0.0 rc0 and rc1 I get video output on all black surfaces, like
wallpaper or fonts.

My system info is:
# emerge info
Portage 2.0.51.22-r3 (default-linux/x86/2005.0, gcc-3.3.6, glibc-2.3.5-r2,
2.6.13-gentoo-r3 i686)
=================================================================
System uname: 2.6.13-gentoo-r3 i686 AMD Athlon(tm) XP 2400+
Gentoo Base System version 1.6.13
ccache version 2.3 [disabled]
dev-lang/python:     2.3.5-r2, 2.4.2
sys-apps/sandbox:    1.2.12
sys-devel/autoconf:  2.13, 2.59-r6
sys-devel/automake:  1.4_p6, 1.5, 1.6.3, 1.7.9-r1, 1.8.5-r3, 1.9.6-r1
sys-devel/binutils:  2.15.92.0.2-r10
sys-devel/libtool:   1.5.20
virtual/os-headers:  2.6.11-r2
ACCEPT_KEYWORDS="x86"
AUTOCLEAN="yes"
CBUILD="i686-pc-linux-gnu"
CFLAGS="-O2 -march=athlon-xp -fomit-frame-pointer -pipe"
CHOST="i686-pc-linux-gnu"
CONFIG_PROTECT="/etc /usr/kde/2/share/config /usr/kde/3.4/env
/usr/kde/3.4/share/config /usr/kde/3.4/shutdown /usr/kde/3.5/env
/usr/kde/3.5/share/config /usr/kde/3.5/shutdown /usr/kde/3/share/config
/usr/lib/mozilla/defaults/pref /usr/share/config /var/bind /var/qmail/control"
CONFIG_PROTECT_MASK="/etc/gconf /etc/splash /etc/terminfo /etc/env.d"
CXXFLAGS="-O2 -march=athlon-xp -fomit-frame-pointer -pipe"
DISTDIR="/usr/portage/distfiles"
FEATURES="autoconfig distlocks sandbox sfperms strict"
GENTOO_MIRRORS="ftp://194.117.143.70/mirrors/gentoo"
LC_ALL="nl_NL@euro"
LINGUAS="nl"
PKGDIR="/usr/portage/packages"
PORTAGE_TMPDIR="/var/tmp"
PORTDIR="/usr/portage"
PORTDIR_OVERLAY="/usr/local/portage"
SYNC="rsync://rsync.gentoo.org/gentoo-portage"
USE="x86 3dnow X aac aalib acpi alsa avi bash-completion berkdb bitmap-fonts bmp
browserplugin cdr cle266 crypt cups curl divx4linux dri dvd dvdr dxr3 eds emboss
encode evo fam ffmpeg flac foomaticdb fortran gd gdbm ggi gif glitz glx gpm
gstreamer gtk gtk2 icq imlib java jpeg kdeenablefinal libwww mad mbox mikmod
mono mozilla mozsvg mozxmlterm mp3 mp4live mpeg mpeg2 mpeg4 mplayer msn ncurses
nls nptl nptlonly ogg oggvorbis opengl pam pam_console pango pdflib perl png
posix print python quicktime readline sdl server slang softmmu spell sqlite ssl
stream svg svga tcltk tcpd theora tiff truetype truetype-fonts type1-fonts
unicode usb userlocales utf8 videos vidix vorbis win32codecs xine xml2
xscreensaver xv xvid xvmc zlib video_cards_ati linguas_nl userland_GNU
kernel_linux elibc_glibc"
Unset:  ASFLAGS, CTARGET, LANG, LDFLAGS, MAKEOPTS

I used spyderous' ebuilds to install 7.0 rc1

If more information is required, please let me know.