Phoronix checked out AMD Fusion on Linux, you can read it over here.
"While AMD was very fast to provide open-source Fusion graphics
driver support under Linux (along with official support in their
proprietary Catalyst driver), the support has not ended up working out
too well for us. It has regressed since the November push. As mentioned
in March, the E-350 Fusion Linux support took a dive in terms of its
graphics support with some outstanding bugs. Since then, the support has
improved and is now largely usable, but there are still some big issues."