A primer on mapping class groups

Benson Farb and Dan Margalit have just finished the final version of A Primer on Mapping Class Groups, to appear from Princeton University Press next year.  And it’s available in .pdf at Dan’s web page.  To the extent I know anything about mapping class groups, it’s because of this book!  Highly recommended for anyone interested in finding a way into this very active area of topology, which has heretofore not been so easy to learn about unless you have the luck to sit at the feet of a master.  Is it too much to say I expect the book to become “the Hartshorne of the mapping class group?”