Michio's point seems to be that because of quantum uncertainty, you can't necessarily predict a future event based on a past one. Watch for yourself.
The Heisenberg Uncertainty Principle may well be in the process of being invalidated: http://www.bbc.co.uk/news/science-environment-13626587
Of course, ther are many different interpretations of QM, some deterministic, others not.
Most physicists I've read seem to believe that the chaotic randomness of the quantum realm is real, not merely beyond our ability to predict. If that question is ever settled, it could have significant bearing on this topic.
Also, unpredictability DOES NOT give you free will. Effectively, an unpredictable quantum process in your brain or anywhere gives the agent no more control over a decision. It is like adding random as a variable.
This is NOT free will. Kaku is NOT a free will philosopher, that is clear from his opinions here. All writers of free will and determinism (myself included) are well aware of the fact that quantum indeterminacy, even if it does exist, does not allow for free will.
Also, "Adequate determinism is the idea that quantum indeterminacy can be ignored for most macroscopic events. This is because random quantum events "average out" in thelimit of large numbers of particles (where the laws of quantum mechanics asymptotically approach the laws of classical mechanics). Stephen Hawking explains a similar idea: he says that the microscopic world of quantum mechanics is one of determined probabilities. That is, quantum effects rarely alter the predictions of classical mechanics, which are quite accurate (albeit still not perfectly certain) at larger scales. Something as large as an animal cell, then, would be "adequately determined" (even in light of quantum indeterminacy)."
Yes, I don't know anybody who thinks that randomness supports free will. It does, however, undermine determinism. Quantum effects in the classical realm seriously undermines hard determinism and the notion of absolute predictability.