So far, the BlackBerry (NSDQ: RIMM) App World has been a destination solely for software, but word has it on November 9, conveniently the first day of the BlackBerry Developer Conference, …the on-device portal will expand to include theme sales. This is a great move, and will immediately differentiate the App World from the stores on other platforms, though the approval process will be something of a sticking point for developers who are used to simply hosting the theme files and letting users have at it. Considering how much trouble unstable themes can be for your BlackBerry, though, I wouldn’t mind the extra layer of quality control. What I am worried about is BPlay simply steamrolling all other theme developers on App World thanks to their tight relationship with RIM. I guess we’ll see what the selection is like at the BBDC.