Well, raiding and mythic dungeons then. I'd have a fit if I as raid leader etc saw a Ret with Equality in either.
So that leaves heroic dungeons, regular dungeons, world content, and old raids etc. And in all those... well you're not going to be getting much out of it in dungeons unless your group is really quite poorly geared or you're doing it for laughs. I'm not sure any spec should have talents designed for the latter :P .
Anyway, then there's world content. Okay, some use here I guess, except that again it's encouraging bad (ie "stand in fire for haste buff") gameplay. And ranged gankers :P .
For old raids etc... well maybe if you're doing WoD content in pre-raid gear it'll help. Not much pre-WoD content that'll get you low though by the time you're L110 and with 1.5M health.
It just seems far too situational for a L100 talent in PvE.
My point is that as a defensive tool I'm not sure it's that great.
It's also quite dangerous from a balance point of view, because there's nothing to warn the enemy that you have this talent. So a couple of enemy melee are trying to burst you down as per usual... now, do you have DP, SW or Eq? Oops, you have Equality, and now two of them are dead with no warning etc. I really dislike mechanics that let you blow people up with little chance for them to do anything about it.
I agree that there's been too much homogenisation, but (eg with mobility) I also worry the pendulum has swung a bit too far in the other direction.
Kiting a Ret pally requires a modicum of skill*, whereas hitting bubble and/or Equality and blowing people up does not. I can't see it staying like that for long. And if you believe Reghame and some of the others in the alpha, Ret mobility isn't even a problem, so... yeah I dunno.
*Be quiet Storm :P .