Seems there may still yet be some things going on with the UI prior to RTM. One can only hope.
given that the Redmond giant has already gone on the record to say that the UI that we see in the Windows 8 Release Preview is not what will be in the final release, it's safe to say that things are in a certain state of flux.
SOURCE: How Microsoft can salvage Windows 8 before it's too late | ZDNet
An interesting read on what might be wrong with Windows 8 and might be done to address it. Nice, brief synopsis.