I'm sure you could... but why would you??
To be honest I could not see AMD comming out with anything that could not be overclocked... I mean thats who they are and why OCers like them. But I also agree that I don't really see the point in OCing a 64 x2. I mean, what more do you want from it, then again their are those that do it for the bench marks and bragging rights. I say leave well enough alone. Learn all you can and feel free to experiment, but go SLOW. I'd say make minimal increases to bus and see if any diff is noticed, watch your temps. Realise... the more performance you want out of your machine the more money you will have to spend keeping it stable. I'd say before you really want to oc, invest in a water cooling kit. Don't take my advice as a golden rule, its just my thoughts and recomendation.