I pledged to write something on Pierre Boulez, but alas the muse and the energy have eluded me.
As would be expected, Alex Ross has posted an excellent memorial piece on the New Yorker's website.
However, I do have one quibble. Boulez was a notoriously slow composer, especially in his later years. Promised new works never appeared, or often ended up being reworkings of older works (not that they weren't often brilliant in themselves), so I always took the talk that Boulez was composing an opera based on Waiting for Godot to be a joke. Finding out that the keen-witted Daniel Barenboim, who waited for decades by a tree on a country road for his commission of an orchestrated version of Notations to be completed, was the source of the this rumor only made it more so.