These are the packages that would be merged, in order:

Calculating dependencies  .... done!
[ebuild   R   ] media-libs/mesa-7.5.2  USE="nptl xcb -debug -motif -pic" VIDEO_CARDS="intel -mach64 -mga -none -r128 -radeon -radeonhd -s3virge -savage -sis (-sunffb) -tdfx -trident -via" 0 kB
[ebuild   R   ] x11-wm/compiz-fusion-0.8.4  USE="gnome -emerald -kde -unsupported" 0 kB
[ebuild   R   ] x11-base/xorg-server-1.6.3.901-r2  USE="hal nptl sdl xorg -debug -dmx -ipv6 -kdrive -minimal -tslib" 0 kB

Total: 3 packages (3 reinstalls), Size of downloads: 0 kB