I just attended AMD's fan appreciation day and was lucky enough to walk out at the end of the day with a Gigabyte F2A85X-UP4 motherboard and an A8 5600K Black Edition as swag gifts (Thanks AMD and Gigabyte!). I'm currently running a Penom II X4 965 Black Edition on an Asrock 970 Extreme 3 motherboard. My graphics card is a Sapphire Radeon 7850OC, so I don't think I'd necessarily be using the integrated GPU on the A8, as I'm guessing it wouldn't add, but likely take away from the system.
Would the A8 and Gigabyte motherboard make it worthwhile to swtich out. What type of performance difference would it make?
I think the swap out would be an upgrade, probably not much though - if used with the HD7850, that should combine for a modified X-fire setup but seeing as how a motherboard/cpu swap would (is suppose to) require a new OS (if using MS OEM), why not throw another $200 into it and make a second computer.
Oh, and congrats on the gifts