Mark Gurman, reporting for 9to5Mac:
Apple is working on iTunes 11 as a version of iTunes that supports their upcoming iOS 6 release and future devices. Apple typically releases new versions of iTunes alongside major new OS’s and mobile devices. While iTunes 11 is built as an iOS 6 compatible-release, according to sources, iTunes 11 could very well be a release coming farther down the road, and Apple could very well release another iTunes 10.x point update as a simple iOS-6-compatiblity release. One source calls that the more likely situation.
OK, so Apple intends to build an updated version of iTunes to support the next version of iOS, and it may or may not be called iTunes 11? Great detective work, Mr. Holmes.