I really don't see much of an issue with NT, but can see where they are coming from.
I did 25M primordius earlier as frost and 52.3% of my damage was NT.
http://www.worldoflogs.com/reports/r...=12933&e=13398. If I had been arcane, I could probably have done about 250K DPS by literally doing nothing but casting NT.
I no longer glyph Icy Veins because it's pointless. I'd rather put up more NTs during IV with the extra haste, on top of the RPPM trinkets favoring ditching the IV glyph, which has always been a terrible glyph to begin with since it's a "patch" for PVE frost having an idiotically low haste softcap under IV.
Killing heroic Ji-Kun earlier, NT was about 18% of my damage without the IV glyph. Quite reasonable.
They will likely make NT have a 3 target cap like LB does. Problem solved. This will not affect mage viability on the majority of fights, and will just force us to hardcast a bit more on the few where multidotting was viable, such as primordius or council. It won't even be that much of a DPS loss if any, since at juggling NTs across 4 targets you were barely gaining anything over dropping to 3 targets and hardcasting a bit more.