Today's New York Times (registration required) provides a recap of what the USA cable companies are saying and doing with VoIP.
For some, like Cox, they keep selling an ATM over Sonet based solution. For others, it seems to be hybrid, leveraging their existing cable plant.
While the concerns about voice quality may have been right last year, given how AT&T's CallVantage is performing for me, I don't think they can stand on that soapbox too much longer.
What the MSO's have to do is bundle. If they want to win the battle they should offer FREE local dialing over their network to other cable customers on their network. That way, they end up sampling the service to their already paying customers.