Music core
The BBC and Channel 4's offerings are essentially catch-up services, whereas any content bought via iTunes can be kept.
The content - available from Apple's iTunes store - can be viewed on TV, iPods or a widescreen TV via its add-on peripheral Apple TV.
Apple launched its video download service in the US two years ago with mixed results.
"Video content in the US has clearly not been as strong as music in terms of both the breadth and depth of what is available and in terms of how much is being sold," said JupiterMedia analyst Mark Mulligan.
While a video catalogue is an important addition to the UK iTunes store, music will remain its core service, he said.
Down the line partnerships with the BBC and Channel 4 could be on the cards, he thinks.
"It is a natural partnership and UK companies have shown a willingness to experiment with online video distribution but a lot of questions remain over things such as usage rights and how to differentiate content," he said.
