It depends on the nature of the channel. Assuming you have all the infrastructure in place to generate the XML and stream the content to the roku the time varies from a few days to a few weeks based on the complexity of the project. A plus if you have your graphics ready already - a significant amount of time I spend working with clients goes to making their graphics look right on roku.
I would be happy to write you an estimate for your channel, please send me an email or a private message via this forum
the videoplayer example is usually in:
/roku_sdk_v29/examples/source/
- Joel
Screenshades: The first Screensaver for Roku2!
Musiclouds: The best free internet music, on your Roku!
Ouroborialis: Psychedelic Screensaver for Roku!