I commented on Om’s blog about this. Basically Comcast will grow with VoIP, but due to all the systems they have gobbled up, it means they have a hodgepodge of equipment.
Since Comcast always wants to avoid the “hassle factor” and tries to deliver a uniform experience to all of their customers, thus streamlining customer service, it will be a longer ramp time than say Cablevision, when it comes to realizing the VoIP dollars.