I'd love to try it on some fools if they organized the Bubble of Death. ;)

Yeah... the other team needed a Striker Titan with Death From Above. That's pretty much the only thing that would have saved them. Well that or a Blade Dancer. :p

They had extra health and shields going, along with the protection of the bubbles. As a Bladedancer, I can tell you they'd need the element of surprise to do any good against that, and with the placement they settled on that's unlikely to happen. Two Bladedancers could be a lot more workable, one gets them occupied and maybe weakens them and the other comes in and wears them down and takes out one or two, then some more teammates step in and use grenades and CQC to clean up.
Multiple Nova Bombs, preferably with Annihilate selected, might also work, but good luck getting more than one or two supers up and coordinated if you're against that and not using the same trick.
Maybe you could send in a Sunsinger Warlock to die and self-revive after a bit as a distraction, on top of some other planning, maybe they could even use the distraction and Radiance to step in and do some damage.
I don't know, the more I think about it the more it seems like there should be counter-tactics, but continuous supers have so much potential to be overwhelming. The shields and the people in them effectively lock down one area of the map, and having Strikers or Voidwalker Warlocks on the same team could let them lock down a whole other section or two of the map with constant area-of-effect supers. This tactic is so effective it makes being a Gunslinger viable (the least useful PvP subclass, IMHO), so I can only imagine the havoc that's possible.