Trash mobs (i.e. non-boss mobs in instances, usually raids) have been the subject of a certain amount of discontent within the community recently. Blizz have said they're thinking about doing something about it, and now they're being a little more specific. Aeus, bearer of good news for the hardcore:
We're going to be making some changes to trash mobs in Serpentshrine Cavern and Tempest Keep, to make them a bit easier, slower to respawn, and provide some greater incentive to killing them.
We'll be continuing to tune and re-tune dungeons and encounters, but currently these are the two we're most concerned with and will be focusing on.
I'm assuming when he says Tempest Keep he means the Eye, the 25-man raid wing of it. So while this is nice for those of us who are working on those raids already (not me), I really wish they would do something about some of the trash in Karazhan. Specifically, the trash leading up to the Curator. That stuff is bonkers. On the other hand, I haven't been to KZ since Tigole said trash in many zones had been nerfed a bit, so maybe it's better now?