Brawler's Guild, Continuation of Horde vs. Alliance War Among Features
Before Mists of Pandaria launched, Blizzard said a few times that their goal this expansion was to release new content faster. So far that plan appears to be on track since they've just announced that the 5.1 PTR will be opening up soon.
Blizzard hasn't released a full list of what's to be expected in the patch, but they did give us some highlights: further developments in the Alliance/Horde battle for Pandaria, phase 2 of Wrathion's legendary quest line, the introduction of the Valor Point item upgrade system, pet battle changes like being able to upgrade the quality of caught pets, and the Brawler's Guild. Most of these we've known about for a while, but the Brawler's Guild is interesting. There's not much info to go off of other than it's solo PvE to earn "bragging rights". Does that mean it's like a Challenge Mode, perhaps tracking rounds completed instead of times? Are there titles or transmog pieces to be earned?
Nothing's listed in the post about new instances or scenarios, but this is just a partial list. If there are any instances or raids, I'd expect it to be just one or two. Rather than having behemoth patches like Icecrown Citadel's 3.3 or Dragon Soul's 4.3, these patches are supposed to be more focused. A raid here, a five-man and some daily quest hubs there - in general the same amount of content, but spaced out to avoid the giant lulls between content that come with the big patches.
Michael "Ragar" Branham