I know people want them, but I worry about future modes.

Jeff spoke before release about how they tested traditional modes like CTF and FFA and found that they didn't work very well given the hero-centric nature of the game. Some heroes become significantly more useful while others are made obsolete. And they didn't want to disable heroes or abilities because it's a very inelegant solution. CTF in TF2 sucked for the same reason; a handful of Engineers at the intel and a handful of Scouts and Spies trying to steal it.

The goal with mode design in games like this is to keep every hero viable. The current modes do that pretty well, but we're already seeing preferences. Lucio is considered an important pick in Control, for example. Speed boost is excellent for reaching the point fast, and AoE healing is excellent for maintaining control of a single area. He also has the survivality to adequately contest a capture. He happens to match the format really well, which makes heroes like Zenyatta or Symmetra feel less appropriate.

I can only wonder what new modes they're testing, which we know they're doing. Does anyone have any mode ideas that could work without overly funneling the hero pool?