Source: Ghostcrawler
The other part of the change that I suppose hasn't been data-mined is that Devastate requires a shield. We hope there is very little interest in an Arms or Fury warrior doing dps with a shield equipped, while we're thrilled if Prot warriors dps with a shield.

Super gZ

what are you telling me

Wonderful change! With the newest build, they're doubling the damage output of Devastate. This solves the dual wield issue they were seeing with Devastate in the Wrath beta while bringing it back up to the same levels as the beta for tanks. It also fits more in line with the sword and board aspect of Devastate in the current Protection tree.

which = a better way to maintain single target threat/boost the dps a bit but still does not address the heroic strike spam or lack of any real aoe tanking abilities

the devastate increase has been old news

this just says "we are covering our bases, dont try any weird shit to exploit this"