The majority of the people who get infected refuse to understand/read anything about their pc/operating system, they just click on buttons till something happens, they disable/uninstall anti-virus programs if they cannot get access to their infected documents or external devices.
Those will never, AND I REPEAT NEVER, accept anything that changes they way they (mis)use their pc out, of free will.
Maybe the only solution is to confiscate the infected pc's (will be difficult in companies) till the user(s) went to school/training after paying a fine for the cost of their unwillingness to be a "good" computeruser.
Till than , bringing down botnets is just bringing water to the sea.
And the source of all of this is the stupid idea of some software companies to create software that does everything automatically by default, because that is a better computer experience.
And YES it will be difficult to sent "Granny" to school, but than the only solution is to hold the makers of the software she is running , responsible (as well) for all the nasty effects that their programs create. (and than the price of vista 2013 will be around U$8000 or more to cover all the costs :) )
All and All it will be a very difficult path to follow and with the trend of today it will take a very long time before there is a real solution.