As the tittle says Running Xen: A Hands-on Guide to the Art of Virtualization is now available to buy, physically of course. So, if you want a copy just follow this link to find out how to get it.
There’s also a complementary website where you can find information about the authors, chapters resources and some other interesting links. Obviously, the authors want some feed back, that’s why they set up a readers list to discus about the book, send your feed backs, errata, and any other topics related to the book.
Nothing else to say. Congratulations to the authors for the great job they did.