What that may mean is: With certain boards that have built-in graphics adapters, you can "crossfire" a plug-in video card with the onboard graphics to get a little boost in performance. They called it Hybrid CrossfireX in the previous generation; now they call it Dual Graphics and it refers to crossfiring a plug-in video card with the built-in graphics on a Llano CPU. It's technically a little different, but the idea is roughly the same.
At any rate, even though you can't crossfire two cards, you may want to look into Hybrid CrossfireX anyway. You may be able to still get some performance increase without paying anything.