So far users have not shown a demand for it. I could see a itunes forum since probably a lot of users have a itunes account. Although how much could you really talk about in the itunes forum ? As for the others you mentioned for all you can eat music services. Seems the demand is very low for that type of provider/service. If the demand was active I'm sure they would add it. The Slacker forum shows that the DRC is willing to expand.