Doug has been so kind to get the Open XML Explained book online on OpenXMLDeveloper.org! No payment required, nada, niente. The soft-code cover costs exactly the same, but is a little harder to come by in the wild (I have my copy :)

Did I also mention that you can get the Open XML workshop content that has been traveling the world online as well? Good days for Open XML developers!

Important update

I forgot to mention that you can (finally) find the demo samples as well on the site. There are also many cool demos in the workshop content for you to take a look at!

ps, that delay is entirely mine, insert lame excuse, sorry 'bout that!

[edit: it was hard-cover, i wrote hard-code, changed that to soft-code, and finally fixed to read soft-cover :)]