As of last night's beta (and PTR) patch, players have been reporting that mob health throughout all of the Burning Crusade raid zones have been reduced by up to 30%. That struck me as really, really odd, so I decided to pop into Sunwell Plateau and Black Temple to take a look. It is, in fact, completely true. Every mob and boss that I could see in both zones (and I could see a lot- Mind Vision hopping through raids for the win) had their HP drastically reduced.
My gut instinct was, "Ugh, why are they nerfing everything so badly? That's ridiculous. Just because it's the end of the expansion doesn't mean they need to make it easy mode for us." Then I actually thought (gasp!) about it for a little bit. Looking at the changes coming in Patch 3.0.2, this was a change they needed to make to let us still raid until Wrath. A lot of encounters probably became impossible to beat as they were with those changes, Sunwell Plateau especially. Sunwell was designed with all of the insanely OP stuff players were doing to win in mind. Stacking Shadow Priests for mana regen, stacking Shaman to chain-cast Heroism/Bloodlust, half the raid going Leatherworking for Drums, yadda yadda.