Found one off the Web -- a similar topic, but here it points a 'rough estimate' of how many users were affected ( noting "that more than 350,000 people will lose their internet connections and around 20,000 of those are in the UK" )
Source article -- DNS Changer: Destroyer of (internet) worlds? Or "Millennium Bug" no-show? : Tech Digest
At least, this is one rootkit infection that won't be easily forgotten