@copsewood
Sorry, but I agree with the original poster in that I believe that it will be very hard for ISPs to detect the issues other than unencrypted communication which can obviously be packet inspected for malware comms. This will just lead to a whole host of disconnection notices for users who do not have malware on their machines, a nice boost for local IT shops and doubtless a few claims of Macs or Linux boxes supposedly running Windows malware.
Your statement seems to revolve around an assumption of ISPs striving for better service etc - you have obviously never lived in Australia. They would like this in part because it will give them the ability to cut off a user and still charge them. Fantastic. The bit they won't like is any setup cost.
Do not confuse laudable (but unmanageable) intentions with the utter nanny-state bullshit that flows out of Oz on a daily basis. I'm surprised that they haven't yet mandated that we all run dumb terminals connecting to sessions they host. This is a country fueled by bullshit and bureaucracy.
I can't wait until a Government department gets disconnected.