I do play tanks, but less so than DPS, mostly because as a tank I just feel like a DPS with some buttons siphoned away from core play and into periodic auxiliaries. With most DPS classes, the pieces seem to fit together a bit more cohesively, at least. Were there more cohesion between the mitigation and damage-dealing aspects of a tank, through both the toolkits of the tanks and (perhaps more importantly) the tuning of the content or relevant undermechanics, I'd probably play the shit out of tanks.
Also, while I still play tanks if I need to rush a Expert roulette queue, there are enough decent tanks out there that queuing as DPS can often win back its difference just through the added difference between my output and another random DPS's vs. my output as tank and another random tank's. Difference as healer is even more extreme, and would probably be the best choice if it weren't, in most cases, even more dull than tanking during an Expert roulette run, if only due to recent healer leveling.