vasy ~ # emerge -av ati-drivers ati-drivers-extra

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

Calculating dependencies... done!
[ebuild  NS   ] sys-devel/gcc-3.3.6-r1  USE="fortran gtk nls (-altivec) -bootstrap -boundschecking -build -doc -gcj (-hardened) -ip28 -ip32r10k (-multilib) -multislot (-n32) (-n64) -nocxx -nopie -nossp -objc -test -vanilla" 23,534 kB 
[ebuild  N    ] sys-power/acpid-1.0.4-r5  USE="-doc -logrotate" 33 kB 
[ebuild  N    ] app-arch/rpm2targz-9.0-r5  3 kB 
[ebuild  N    ] virtual/libstdc++-3.3  0 kB 
[ebuild  N    ] x11-drivers/ati-drivers-8.32.5  USE="acpi opengl -doc" 57,133 kB 
[ebuild  N    ] x11-drivers/ati-drivers-8.39.4  USE="acpi (-multilib)" 39,146 kB 
[ebuild  N    ] x11-apps/ati-drivers-extra-8.32.5  USE="-qt3" 0 kB 
[blocks B     ] x11-apps/ati-drivers-extra (is blocking x11-drivers/ati-drivers-8.39.4)
[blocks B     ] >=x11-drivers/ati-drivers-8.33.6-r2 (is blocking x11-apps/ati-drivers-extra-8.32.5)

Total: 7 packages (6 new, 1 in new slot, 2 blocks), Size of downloads: 119,847 kB

!!! Error: The above package list contains packages which cannot be installed
!!!        at the same time on the same system.

For more information about Blocked Packages, please refer to the following
section of the Gentoo Linux x86 Handbook (architecture is irrelevant):

http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?full=1#blocked

vasy ~ #