Well, nothing they can do to boost PvE survivability is going to affect shaman representation in arenas; the class in general is broken to begin with, the problem being that the effectiveness of the character is too easily shut down - something a PvE fix is not going to affect. Another discussion, perhaps.
However, it isn't terribly difficult to revamp enhancement's upper-tier talents to WotLK-level effectiveness (as many other classes got) - which hasn't happened because likely the developers responsible for it have a different mindset into how talents should work for shaman (just speculation, but isn't it odd how all but the very latest-changed enhancement talents are single-function, whereas the elemental / resto talents are nearly all multi-functional?). The simplest fix with zero effect outside of enhancement would be to add 20% extra HP to the Weapon Mastery talent. Tada, fixed.