I don't think the Llano chips are going to be able to work in an AM3 motherboard. If you have a motherboard with an integral graphics chip like a 790GX which is what I have, it will have to be able to either take over the VGA. HDMI, or DVI connector from the onboard graphics chip, or crossfire with the onboard graphics chip.
Unless the current generation of onboard graphics chips were designed for that, I don't think the graphics chip driver programmers are going to be able to retro-fit that capability with driver upgrades. And in the case of boards, without an onboard graphics chip what are they going to do for VGA HDMI, and DVI connectors?
I'm pretty sure that even if Llano can use the AM3 processor socket, they still won't be able to get the graphics off the motherboard and to the monitor with any existing motherboard.