Today's answers are short, but it doesn't mean that I don't love you. It just means that the questions didn't require long answers, and also that someone thought it'd be really funny to post the same comment half a dozen times on different accounts, each comment acquiring half a page of replies saying variations of "shut up already." Nice work by all involved.
Above is the first single from Justice's new album, Audio. Video. Disco.
Who are the Mogu, and have they been around in lore even before MoP?
They're the old masters of the Pandaren, and no, they have not been around in lore prior to this expansion announcement. The most important thing you need to know about the Mogu is that they look like Foo Dogs, and that makes them awesome.