Anthony,
It appears that you select "activities" rather than "devices", and you use the little scroll wheel thingy to select which one.
This could work quite well, but the lack of number keys could be a problem. Maybe you have to set up "Watch channel 7" and "watch channel 9" etc. as activities (can you ???).
Possibly they do require you to regularly log in, and download TV listings, so it knows what shows are on in your area right now (assume built in clock), and displays "watch Jeapordy/Auto Racing/Friends as shown on the web page. I could see that being a real pain for us non US users.

I agree, if they make software available to let the user do their own customisation WITHOUT HAVING TO VISIT THEIR WEBSITE, this could be a great tool/toy.

Ric