Heres a great way to fix this problem, make it so if you have more than 1k resilience you cant que for a dungeon.
Of course this doesnt keep people from putting on another set for another spec to counter act this but it would help alot with the PvP people queing for dungeons.
[edit]: Also another way is to make it so the Ilvl from PvP gear is lowered... sense it has no purpose to begin with.