ICANN's current stated policy is to not cause technical problems. For example, they will never open up .local. But if people start succeeding in popularizing whatever TLDs they want, maybe ICANN would change that policy just to screw with them.

Still .bit isn't going to work today without special configuration, so it's not at all clear that publishing it from the root servers would break anyone that was already successfully using it.

Presumably, anyone friendly to the alternative DNS effort (ie. anyone running a .bit-capable DNS) would serve the p2p .bit domains over the ICANN domain that case. Although it would certainly be interesting.