A brief digression from C# 5 to talk about C# 4: the annotated C# 4 specification is now available in book form from Addison-Wesley.
It is of course handy to have a specification in book form, particularly if you're going to while away the hours with the book sitting by a warm fire. (It's hundreds of pages long; you can keep a fire going for hours.) But the real value-add of this edition over the downloadable version is that the print version is heavily annotated by numerous people who know a thing or two about C#. This edition features annotations on almost every aspect of the language from Brad Abrams, Joseph Albahari, Krzysztof Cwalina, Jesse Liberty, Christian Nagel, Vladimir Reshetnikov, Marek Safar, Chris Sells, Peter Sestoft, Jon Skeet, Bill Wagner and me.
Mads and I thoroughly reviewed all of the annotations from the previous edition to make sure that those which carried over all made sense in the new edition, and there are many new annotations as well. If you have suggestions for areas that could use further annotation in future editions feel free to post comments here and we'll consider them.