In order to last longer and be more effective over the course of the fight, you won't be using miasma and unlikely you'll be using shadow flare without using swiftcast along with it. At this point, you'll start dipping below 200 dps. Even if you were to include raging strike in this situation, where the dps matters (in boss fights of course) you'd potentially only see a overall 6% increase in damage if even that high.

In short, unless you ignore the red circles and never move, have perfect situational awareness all the time with your dots you aren't going to be hitting that 200dps marker with any sort of regularity in boss battles. Unless there is a bard or two to have mana song on all the time right now summoners are sitting around 190 to 200 dps realistically. Lets not even say if there were multiple mobs spread apart that you had to target; dps would drop like a rock and it would take at least 10 seconds to get going on new targets.

Lastly, this 1000char limit is lame.