From what I gather through reading the thread, it's a huge change in Enhance play-style for a ~4% gain in absolutely ideal conditions, assuming no nerfs from Blizzard for Enhance valuing a caster MH weapon. Although it does raise the question, why would they make a SP axe when only Shamans and pallies can use it?
Enhancement shammies are weird they are a melee class that does a lot of spell damage and has a mastery that boosts spell damage. Yet Blizz gets mad when they start to use caster MH weapons as they were even starting to get there in 4.1 with MH weapons with barely over 2.1s swing speeds. Then the WF buff made the fast weapon speeds cost too much potential damage so the concept was put on hiatus.
What Digg said is very true. Making that axe is like a giant tease, slow enough to make WF still hurt yet with enough SP to make hard casting an option.
Enhance needs some serious work. The spec is a great example of a great design idea that is a failure when executed, well at least this iteration.