Works here:
# pacman -S testing/xorg-server
resolving dependencies...
looking for inter-conflicts...
Targets (7): xcb-proto-1.2-1 libxcb-1.1.90.1-1 libx11-1.1.4-3
libpciaccess-0.10.3-1 pixman-0.11.8-1 libdrm-2.3.1-1
xorg-server-1.4.99.906-2
-- Hugo