Taking a cue from web browsers, how about implementing an option of a dedicated button on the remote for "home screen" - the landing channel of your choice.
Without something like that, let's say you are browsing channels through the "my channels" app, and you click on a channel and then want to return to "my channels" you in fact do not - you actually return to where the channel resides outside of the app. From there you have to travel left or right to find "my channels again. It's burdensome and needless. It would be so much more convenient to be able to default to a particular channel which would more likely than not be a personalized channel app such as "my channels."