The newest rumor to hit the iPad circuit is the possibility of a radio-like or streaming music service. 9TO5Mac discovered icons within the iPad version of the Music app that featured a radio antenna and had the word 'buy' in the icon's name. Interestingly enough, the iPhone version doesn't have these icons.
Of course, it's a pretty big jump to assume a service based on a couple of unused icons. When I first started developing mobile apps, I left a couple of screenshots in an app. The screenshots were meant for the iTunes page, but anything within the directory structure gets bundled with the app package no matter if it is used or not. And while the icons indicate Apple may be at least thinking about such a service, we can't rule out a member of the development team with a sneaky idea for an Easter egg.
However, there have been rumors that Apple wants to build their own Pandora-like service. Most of the focus these days has been on the iTV rumors, but Apple did say they had a couple of new products in the pipe, and a streaming music service could be one of them.