Hey M,
It would be most helpful in your post if you mentioned what/why you need a Dual CPU Mobo. What kind of software you are going to run, system use(Server, Hardcore gamer, whatever).
It might also be better to wait until the Thoroughbreds are released first. I have not seen any mobo's claiming to be made for any Thoroughbreds single or dual, so it would be hard to recommend a mobo based on experience or reviews.
By "dual athlon Tbred" do you really mean Dual Athlon MP?
As far as Dual Athlon MP mobo's go, both the MSI K7D Master & Asus A7M266D look like good choices. If you are not a "end-user", I would go with the Asus mobo. If you are just a end-user, I would get the MSI mobo. The reason is Asus makes the best quality mobos out there, but doesn't give a Jack unless you are a OEM, so forget about tech support........not that anybody really has "great" tech support these days. Good Luck
Peace Out.............tile
Just waiting for the next "Big" thing like everyone else?