Out of home streaming is via IP. In home to 2nd screen devices is via IP. 3rd party content partners are IP, like HBOgo. Internet customers require IP over the cable plant. Those things will never change. Video-QAM works fine, but if you're going to expand your services to more devices, you'll have to keep 2 technologies forever, or you can choose one that can do both. The amount of headend equipment is cut in half. Even better, new services in the future would not require new headend equipment, but are just software services living in some server way way up the city or regional, maybe even national network.. Replacement box costs? Most TV's sold today can decode mpeg4 and have IP stacks. As well as all the tablets and smart phones. And all the streamer boxes. This is actually reduced box costs almost free, the customer paid for them. Anyway, I don't think the cost is an interesting question. They look at it as what services can they offer to increase revenue. Advertiser or Customer revenue. Even the most basic, how is Comcast going to roll out more OnDemand screens? Switched Video-QAM and an IP request channel? Or an all IP channel? If Comcast doesn't move into these segments, the customer will go to Apple or Amazon and Comcast would lose that revenue. There's a whole other topic of ad insertion, I'm not going into.