Only AMD can tell you whats the upgradability and compatibility of CPU's to come... Usually and from what i've seen from AMD recently they will be compatible with current boards with just a simple bios update... and i guess that even when Socket AM3+ gets here everything should continue rather compatible if they want (which i think they do).
AM3 boards shouldnt have any compatibility problem with newer CPU's for a few months/years something tells me that even when octacores get here they are probably gona be compatible, unless AMD intruduces a completly new arquitecture for those. With luck even when AM4 gets here for DDR4 your board might still accept new CPU's through a simple bios update...
Well this is on the AMD side, you also need ASUS to keep up of course, but asus is a cool company they'll will most certainly back AMD up =)
Its AM3, so will most likely be socket compatible, but may or may not get the necessary BIOS upgrades. I would imagine that it would, since its a good ASUS board, but its not a guarantee. I would bet that it will though.