You're not alone. To try and put things into a nutshell:
- With elements of play like the new spirit-to-hit conversion and new talents and abilities, some casters are reporting greatly inflated DPS.
- Meanwhile, with the loss of stats like armor penetration and tinkering with buffs like Windfury, melee DPS of all stripes are reporting DPS losses. Some classes are reporting as much as a 50 to 60 percent drop. Some of this is probably due to suboptimal gem or gearing options. ArP's switching to crit like it did basically loaded up a lot of people with far more crit than they needed, as one example.
- Healing is in a weird place. Resto druids miss their forms, and across the board, heals are reported to be slightly less efficient -- but since no one's leveling past 80 yet, rating decay isn't crippling anyone.
- Tanks are reporting significant issues in trying to tank the current content with the new systems. AoE threat is greatly reduced for just about everyone, and learning new mechanics is causing some difficulty. For instance, if you spam Heroic Strike as a warrior tank now, you're doing it wrong. Armor has decreased in many cases, the loss of defense has cost tanks who relied on that stat some pure avoidance, and in general, the greatly inflated DPS of some casters has made keeping threat off of them extremely brutal.
This is it! Patch 4.0.1 begins the slide into December's upcoming expansion. It's a whole new game from here on out. Get oriented with our roundup of everything there is to know about patch 4.0.1 and how it changes the game until the launch of World of Warcraft: Cataclysm.