I have been a fan of Thomas Piketty's work for nearly a decade, particularly his work on wealth concentration in France over the long run (click here). Indeed, his papers on wealth concentration inspired me to write an article on wealth inequailty in Ireland over the long run using probate data.
The publication of Capital in the Twenty-First Century, his 685-page book, has turned him into a 'rock-star economist', with sales of his book propelling it to the top of the best-seller lists. His book is controversial. Using long-run data on wealth, he argues that Western societies are returning to their unequal past, where wealth and income is concentrated in the hands of the few. However, it is his explanation for these events as well as his radical policy prescriptions, such as international wealth taxes, which caused the most controversy.
The review of Capital by Robert Shiller is here and Evan Davis has a nice piece at the Spectator, comparing Piketty with McCloskey (see short video below).