> The current crop of controllers are optimized for low power, which fits the e-reader use case but that is not optimal for the interactive use case.

Eink is awesome for low-power use. Why try to contort the technology for something it's not good at, instead of using a more appropriate technology like transflective LCDs? Eink isn't the only option for reflective displays. If you increase the power use of eink to get better refresh rates, I imagine you'd end up using more power than (and still end up with lower refresh rates than) an MIP display.