I suspect quite a few players will be seeing the level 90 version of the Brewfest holiday boss, Coren Direbrew, for the first time this week. Last year's Brewfest arrived so soon after Mists of Pandaria launched that you had to level somewhat quickly to be able to queue for Coren at all. Fortunately, that's no longer the case, so now you've got a choice. You can get better gear for yourself and approximately 37,000 alts off the Timeless Isle if you've a mind to grind, but killing Coren can get you some ilevel 470 trinkets without having to suffer endless "Is Huolon up?" spam in general chat.
That might be worth it. It's up to you.
Anyway, right now there's no indication that Blizzard has changed the holiday in any substantive manner, and [the developers said very recently at Gamescom](http://www.mmo-champion.com/content/1345) that there aren't any plans to overhaul holidays in the near future.
This year, Brewfest runs from Friday, Sept. 20 to Sunday, Oct. 6. As always, check your in-game calendar for your server's exact start and end times, as they'll differ slightly by time zone. The Brewfest meta Brewmaster is required for the year-long What A Long, Strange Trip It's Been, so you'll want to get this done if you're working toward a Violet Proto-Drake.
If you're leveling a monk who plans to tank, the Brewmaster title is basically mandatory. And yes, the Orgrimmar Brewfest area is smack in the middle of what's canonically a war zone at present, but when has free booze not trumped violence?