You are correst, the old micro console controller will not work with the tablets. They are releasing a new model that will be usable on all devices, supposedly even with TVs with built-in OnLive.
Regarding the recent announcement of a Onlive universal controller, I prefer to use my wired xbox controller with the MicroConsole, and I would love to use the wireless controller that came with the Onlive micro console exclusively for my iPad. However, it's sounding like the old MC controllers won't be compatible. Of course, I'd LOVE to be wrong on that... Thoughts anyone?

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