Several people have asked me privately to let them know when the book comes out. It seems e-mail is the preferred method for those who (for reasons I can’t possibly fathom) don’t feel like keeping up with the Social Web. So I created a mailing list for the Xcode 4 Book site.
For those who want details: I used Mail Chimp to create and manage the list. Since I’m using WordPress 3, I downloaded the sign-up list plug-in supplied by Mail Chimp. I don’t plan to send frequent updates, only major news (like the release of the book or a new edition, etc.). Of course unsubscribing is an option.