I would like to throw in my vote for a Roku Channel as well.
For the developers who review these posts: take a look at the top selling digital media devices on Amazon. 3 out of the top 5 devices are Roku. The three Roku varieties are 1, 2, and 4 with Apple TV and Boxee box throw into the mix. It's getting all sorts of press right now as being the best Digital Media Device out there with none of the issues plaguing Google TV options and it has a low cost of entry. Pandora and MOG and LastFM are already available.
Slacker (In my opinion) has so much more to offer I would think it would draw a large number of Plus subscribers.
Here is a link to the developer program:http://www.roku.com/developer
If you have API's there are a number of active developers on the forums who I'm sure would be willing to work with you to create a Private or Public channel if resources are the concern.