If you were to ask a random rogue how the class is doing, you would receive one of a dozen answers. Many rogues are frustrated with the class' transition to passive damage and the meager number of actions we perform to maintain our rotations. I have met rogues that are both extremely disappointed and incredibly enthusiastic about how we're competing in PvP. For every subtlety rogue that longs to have Preparation back, there's an assassination rogue that is praising Shadowstep's usefulness.
If you take an empirical look, like our friend Rfeann suggests, you'll see that rogues are doing quite well in Mists of Pandaria. Assassination rogues are sitting at the top of the melee DPS classes in Mogu'shan Vaults, and of course we're untouchable on the combat-friendly Stone Guard encounter. We're not at the same ridiculous level of DPS as we were in patch 4.3 with our legendary daggers, but we're still making a name for ourselves against raid bosses. Why are so many rogues discontent when we look to be doing so well?