I first want to say: please make a Atramedes plushie Blizzard. I would buy one, maybe two, and love it oh-so-much. Pretty please?
This expansion's most adorable dragon has very few changes in heroic mode. You have less gongs to hit (essentially a soft enrage timer and less wiggle room to screw up) and things tend to hurt more and there are more bad things to stand in spawning during air phase.
The new mechanic is that little obnoxious adds spawn, monkey-themselves onto someone's back, and cast a spell appropriately called Obnoxious. Set DBM to announce when they spawn AND when they are actually targetable, as they'll be out for a few seconds before you can damage them. Once you can target them (having an addon like Tidy Plates is useful to see them) switch to them immediately and interrupt their casting as much as you can. They don't have much health so they'll die pretty quickly.
Of general importance: (1) pop shammy rage/stoneclaw totem on Searing Flame (2) ghost wolf during air phase, *especially* if you're targeted by his beam.
Sonar Pulse always spawned and headed in a straight line and we could just strafe left or right. Similarly, a player targeted with Sonic Breath would always run left or right and we would know to run opposite. When the adds spawned we were also always close enough to kill them in seconds. Being this far back did mean our kitty druid or hunter would have to sacrifice some dps to run out to a gong from time to time (we used them up back to front), but it was worth it for the ease of dealing with the other mechanics.
This is the last of the heroic strats as 4.2 came out and we've been focused on downing the new stuff.