Last year I wrote about how you could sneak a low-level character in to kill Coren Direbrew (through some LFG trickery) and net some nice XP and early loot. I was very surprised to see that, for the most part, this trick still works this year! Here's a quick rundown on how to do it.
Note: the minimum level to queue for Coren normally is 84.
First things first: killing Coren will get you the Direbrewfest achievement and a chance at the level 85 trinkets, but you will not receive the Keg-Shaped Treasure Chest that has a chance of containing the shanker, remote, tankard or one of the special mounts. So if you wanted the Brewfest Kodo for your level 55 character, sorry but you're outta luck. You also will not receive any significant XP.
Basically, you need to have someone queue for Coren, zone in, and then drop group. Someone else in the party then needs to invite you, allowing you to Teleport to Dungeon and be there for the kill, achievement and trinkets.
In other words, simply get five guildies/friends to queue, and then one person can drop, allowing one of the other party members to invite your lowbie character.
If you don't have a full group, I would NOT do this trick! For one thing, it's unfair to make random PuG strangers carry your all-but-useless lowbie character through this fight, even if it IS really easy. Unlike last year, where Coren was a ridiculous pushover, some groups will legitimately miss the loss of one DPS. Also, even if you DO win, it's DEFINITELY unfair to steal one of the trinkets away from someone who actually earned it.
Secondly, and this has changed from last year, the person who drops the group so that you can join no longer gets a deserter debuff. This means that it's much easier to get a group of people to do this, since you're no longer "sacrificing" one character's time by slapping them with a deserter debuff each time you swap a lowbie in. Just get a group together and do it over and over again, rotating in different people's low-level characters to get them the achievement and early trinkets. It's a very nice bonus for characters who are close to 85, but who probably won't actually reach queue-able level (84) before the event ends.
We tried this out with a variety of lowbies, and it looks like as long as you are high enough level to queue for Blackrock Depths (where Coren is located) you can do this trick. If you are below this level, however, you will be unable to use the Teleport to Dungeon option. I'm not actually sure what level this is, but I assume it would be around level 44-45.
BONUS BREWFEST LOWBIE TIP: Even if you HATE the Brewfest Ram-riding quests and have no intention of collecting the tokens, it is totally worth doing the daily quest where you ride the Ram and collect kegs. Why? Because you don't even have to DO the quest to receive the rewards! As soon as you accept the quest, you get mounted on the Ram...AND receive your XP/gold, right away! So you can just right-click off the Ram buff, and leave. The XP is nothing to sneeze at - it's good for 2-4% for only a few seconds work. So get your lowbies out there and cash in!
The quest (called Brew for Brewfest!) isn't immediately available, but to unlock it you only have to do a few simple preceding quests, Now This is Ram Racing... Almost. and There and Back Again. (If you REALLY hate Ram riding, you can actually right-click off the Ram buff for There and Back Again, and just ride a normal mount to the NPC who tosses you the kegs. This doesn't work for any other quest, sadly. Thanks to Normande of Flavor Text Lore for pointing this out!)
Once you do these quests, the daily will be available each day for the rest of Brewfest!