ComputerBB

Ok, you heard the AMDK8 news. So what did you do. That's right, you bought a Socket 754. Oh no, Socket 939 is coming out. Don't panic, you have the ultimate motherboard. Simply sell your CPU and buy a socket 939 one. No motherboard replacement. Of course this situation does not come with an ordinary motherboard. It comes with ASRock's K8 Combo. This motherboard can either take a socket 754 or a socket 939. Now, upgrading is less painful on your money. Now, you save. Get more details here.

Also comes in socket 478/775.

No, you can only run one at a time.
I think the article says that.
"either a Socket-939 CPU or a Socket-754 CPU, but not both"

Oh sorry, I didn't read the full article