8 core? I guess that depends on what you mean by core now doesn't it?
Rumor says there is an AM3+ coming. Should be ok with AM3, and even some AM2+ combos MIGHT work as well. As Hunter said, they will have to do something semi soon if they want to do some things. As for performance, nothing is known at this point. I'm not sure they even have working silicon at this point, though I think I read recently they just started sampling to partners. (might have been the new 6xxx cards though.) IF BD does come in its current form, I doubt it will be much faster then what they already have. Because of how AMD is planning on calling a "core", a "quad core" in some cases might not even be as good as the current line up.