I am just curious: are you going to make a WinRt app or not? The desktop app is actually a bit of a pain on a Surface Pro, and I won't buy a Surface RT until there is an app for it. An RT app could also integrate into the features with Windows 8.
Come on. Do it for your customers. I would buy a premium membership if there was an RT app, but without it, I can't justify it.
I am waiting since November 2012 for a Metro-App... gonna cancel my premium account soon and buy xbox music pass instead, the costs are the same and it works fine with Win 8, Win RT and Windowsphone 8.