Although it's no longer the first week after patch 3.1, when Ulduar nerfs and other hotfixes were coming almost as fast as we could post them, Blizzard is still fixing up the details here and there. Over the past week, a few hotfixes have gone in. Fortunately, as they have been doing recently, Blizzard has posted a nice list of what those changes are.
It's nothing too earth-shattering, as far as I can make out. Some creatures associated with the Yogg Saron fight should load faster. A few items have had their stats buffed (Earthshaper, Valorous Siegebreaker Shoulderplates, and Conqueror's Siegebreaker Shoulderplates), while Leviathan's Coil had its armor cut roughly in half. Clever DKs can no longer cut their RP costs with items meant to cut mana costs, and a bug involving Leviathan MK II's Self Repair on Mimiron was fixed.
Most recently, along with warrior buff shouts being made free again (as they should be) during preparation in arenas, Blizzard has seen the need to remove all non-boss chests in BC dungeons. They say this is "to resolve an exploit;" I assume it has something to do with people being able to farm chests too easily.
It is disappointing when fixes like this happen. On the one hand, it's "only" BC content, and chests aren't going to make or break a dungeon. On the other hand, those dungeons are deserted and useless enough as it is, and Blizzard keeps telling us they think there is still entertainment value in the old zones. Hopefully they get the chests fixed up eventually,