Patch notes for 4.2 - take a look.
They removed the proposed cooldown for spell steal!
"Aetherna does a happy dance."
So, OK, yeah... it's twice as expensive. I can deal with that. Just so long as I can blow a chunk o' mana to (arcanely) reduce Mr. Superbuff to a shivering, almost-naked meatsack that's just a PoM Arcane Blast away from getting a first-hand view of the afterlife, well, I'm happy.