Well-geared hunters, rejoice: you're getting buffed. According to Ghostcrawler, hunter DPS is too low at the moment, so the damage of all ranged weapons with ilvl 226 or higher is being increased by about 30 DPS. This includes drops from Kel'Thuzad-25 and Ulduar-25, as well as Furious Gladiator gear and Ulduar-10 hard modes. This is estimated to result in an overall DPS increase for the hunter of "a few percent."
The reason this change ended up needing to be made has to do with what they wanted to do with ammo in patch 3.1. They had grand plans for an ammo revamp (which I don't think they've ever quite revealed), and as a result they stopped designing new tiers of ammo, so raiding hunters now are stuck with the same bullets they were using at the start of Wrath. This change rolls the DPS from non-existent higher tiers of ammo into the weapons.
Ghostcrawler also mentions that they think hunter DPS will need more improvement, and that there is another buff that they're trying to roll out "sometime in the next couple of weeks." We will, as ever, keep you posted if we hear anything.