How to apply to have your channel included in the store, or how to apply to start building the channel (i.e., do you have a completed channel yet?)
To create the channel (if you haven't already), sign up as a developer, and download the SDK (or alternatively look at the list of developers for hire at the top of this forum and hire someone appropriately).
If you already have a channel, I take it you have the SDK, which documents about the submission process, so you should be able to look there.
-- GandK Labs
Check out Reversi! in the channel store!