Buried in the middle of the healer session of Ask the Devs is a quote that pertains to dps:
We had originally planned on having bosses in later tiers scale so that players would need more crit, hit, expertise, dodge and parry for later tiers. We ultimately decided not to do this, at least for the current expansion. That decision was driven partially because we couldn’t figure out an elegant way for stats like haste to scale with boss power and partially because we weren’t convinced our planned UI would communicate the concept clearly enough to players. For example, would just bosses be affected? Just raid bosses? If not, would you want separate sets of gear for dungeons vs. raids? Those are solvable problems, but we weren’t convinced the path we were on would solve them as well as we would like.
This is why we did not need more hit for Firelands and it is why we won’t need more than current levels of hit for the rest of the expansion.