M. Zwolinski has a piece up at libertarianism.org on Basic Income.
Compare and contrast with Munger's comments.
My chief objection (if you can call it that) is that there's a robust market in paternalism fueled on the left and the right alike, both supply and demand. Ending the kaleidoscope of transfer programs faces severe transitional gains problems and may not be longitudinally stable.
It's still a very fine idea to ponder though.