If you like being spoiled for patch 2.4, that would explain what you're doing here. Nevertheless, in the spirit of postings that revealed details of the Kalecgos and Brutallus fights, here's a peek at the M'uru fight, starring everyone's favorite naaru, the source of blood elf paladin's stolen powers, now remarkably less bright and shiny than you might remember him.
It seems that M'uru is hardly a pushover. In the spirit of not giving out too much detail, I'll leave it at that. It's hard to get too specific about the fight anyway, as you'll see as you watch the video. However, previous lore about the naaru life cycle seems to be confirmed by the video.