I was on a break from WoW when Brewfest hit last year but my previous experiences of Brewfest was that it was a quest based daily, so I could farm the mounts with my Shammies.

This year, it seems you can only use the Dungeon Tool to get to that boss - if you just go to the bar, he isn't there.

That now means that neither my Shammy nor Mage teams can do him, even though both teams would melt him much faster than my mixed team do