I did an extremely rough sim in my head, and casters I think come out on top with pvp MH/OH compared to the best sha-touched staff (no caster 1H only healer atm), losing about 7-8% spell power but gaining approx 10-11% pvp power (based on wowhead's estimated @ lvl 90), but yeah I figured anyone who is weapon damage dependent will lose out.
Stupid move by Blizzard, glad I'm rerolling a caster