Going to get dog-piled upon, but does MM seem a little watered down in Cataclysm? I'm not begrudging the DPS or usefulness, but the spec seems to have a ton of passivity. Trueshot Aura, Wild Quiver. Aimed Shot is back to being a PvE spell, or just an opener in PvP + Camo. I'm not sure how the new damage/health mechanics work in Cataclysm, just that 5% health every 6 seconds does not seem that useful for what was lost with Chimera Shot and our associated Stings. Granted, with the new changes to damage/health (or promise), Disarm is trivial, even if everyone didn't already use a weapon chain, and mana draining could be devastating (and we don't even need the drain to restore mana), so I can see Chimera Shot needing retooling, but a healing shot?
Hopefully without deriding my knowledge (or lack thereof), someone sell me on the awesomeness of the MM in Cataclysm.