In a forum thread discussing the recent prot warrior block changes and Warbringer nerf and the state of prot warrior DPS (it's basically acknowledged as the lowest DPS among the tanks) Ghostcrawler chimes in that they intend to buff sustained prot DPS while reducing burst in PvP. However, he quickly comes back to point that at this stage in the expansion they don't want to make any sustained mechanical changes and so, don't expect one. The sustained DPS increase will come from buffs to existing abilities.
While I can understand the trepidation from prot warriors at this statement (no one is terribly excited about a buff to Devastate, not even me) it's an unfortunate but valid point he makes here. You really don't have the time to make drastic mechanical changes this far into the cycle. We might like a more drastic solution, but with Cataclysm looming on the horizon you don't really want to see too much tinkering with the base mechanics.
Still, please don't just buff Devastate. Please. I'm begging you here.