So I've been leveling a horde death knight. Mainly just to try out horde stuff. Orginally he was going to tank, but that's on hold. I still have my level 17 warrior to practice tanking with. Anyways, that's not the point.
The point is that wow, death knights are buff! I mean, my gear _sucks_. This is my only character on the server. No heirloom gear, I haven't gone to the AH to upgrade his gear since he was made. He's literally in all quest greens, with his weapons being maybe underleveled by now. But I get top DPS meter nearly every time in dungeons. Not only that, it feels like I always have tools for the situation. Pull aggro? There's an app for that! I have an anti magic shell and IBF, chains of ice, run away like a little girl until the tank can save me. Mob eating the healer's face? zot! GET OVER HERE!!! Its just crazy the survivability yet amazing dps.
And then there's PvP! I feel STRONG. Now, this is still while leveling, but all the extra abilities really make a difference. Mages simply have no chance. Done. Blink? Lulz. I think the hardest for me is probably ret paladins, because they can outlast me with heals.
One thing I've really noticed is the huge difference between PvP geared people in BGs and non, because I'm actually a class that doesn't just fall over because I stood in the wrong spot and a hunter tabbed over to me. People my gear level have it coming to them, but people who are in 70 pvp gear, I get them down maybe 20% before they smash me, it's a huge difference.
Now, this was BGs at 70, so maybe things even out. DKs seem much less common now at endgame. I know they were pretty powerful, but everyone seems to think they got nerfed through the floor, but right now, it sure doesn't feel like that. Maybe I shouldn't say anything :X