WotLK Heroic Mobs hitting much harder

[Aquiline]

I remember being able to tank afew hits as a dps in rdf but recently I found out that the heroic mobs are hitting extremely hard. I dont have the stats to prove it but i'm pretty sure something changed in terms of damage done by mobs. Are there any recent changes that might have caused this?

[Blind]

You kinda need to be a bit more specific about the dungeons in question.

There are a few dungeons with much more noticable difficulty spikes compared to others or even their own normal version making a general statement quite hard.

[Aquiline]

My observations are from rdf hc mobs. I remember being able to tank as a bis fury warrior or a bis ret paladin without much difficulty but this few weeks, something has changed, a simple elite mob is able to kill me within like 5seconds without heals which isn't the case last time.