Yesterday Paul Krugman and David Brooks opined about Thomas Piketty's new book, with Brooks emphasizing human capital (and some Marxian class conflict theories of his own!). Krugman wrote about this issue in his formal review but doesn't mention it here. Ironically, this seems like a focal point at least for U.S. inequality: much is driven by high returns to managers at the top. It's not obvious whether better educating the bottom, as Brooks suggests, could help much, but perhaps he's positing that anyone with enough education could break into those ranks of the hyper-successful.
Update: Greg Mankiw weighs in as well, and mentions an AEA session upcoming in Jan 2015.