Methods and apparatus for delivery of packetized content (e.g., video, audio, data, etc.) over a content delivery network. In one embodiment, the content is packetized using an Internet Protocol (IP), and delivered by a service provider over both managed and unmanaged networks to subscribers of the provider, so as to provide delivery at any time, at any location, and via any designated user device. The delivered content may originate from the service provider, third-party content sources (e.g., networks or studios), the subscriber(s) themselves, or other sources including the Internet. Use of a common control and service functions within the network afford the ability to integrate or blend services together, thereby affording the service provider and subscriber new service and economic opportunities. Content delivery sessions may also be migrated from one device to another. A network-based user interface infrastructure, and gateway-based client-side architecture, are also disclosed.