Motoko Rich describes a trend toward quick turnaround on certain "of the moment" titles. It's true -- for certain manuscripts, it only makes sense to insert them into the conversation as it's happening.
An example -- Richard Posner, who in addition to cranking out esteemed books on the law at an astonishing clip, finds time to maintain a day job as a judge on the United States Court of Appeals for the Seventh Circuit in Chicago (where, unlike many judges, he writes all his own opinions) as well as a well-regarded blog on legal matters, let us know that he wanted to do a quick book on the current economic crisis, to be called A Failure of Capitalism: The Crisis of '08 and the Descent into Depression, which could serve as concise and non-technical examination of this mother of all financial disasters -- you won't have to dig out your old macroeconomics textbooks to get through this one. This is a book where it makes sense to pull out all the stops, and we did -- we turned it around as fast as we possibly could and got galleys out there (Tyler Cowen is reading one), and will publish in May.
The only tricky thing with books like these, other than rearranging everyone's schedule, is to know where to stop. The event -- in this case, our ongoing financial crisis -- continues, but the book has got to end somewhere so that we can print the thing. This is where the internet, in all its flexible mutability, comes in -- author blogs are nothing new, but with books like this they acquire a real, important function and increase the book's effectiveness and utility for a reader.