I posted it on my blog, so I guess I can say it here, too -- some things have changed, and
Sunborn will now be released as a Tor ebook. I have been assured that this will happen near to the release date of the hardcover (end of October), and that it will be available as a DRM-free file.
I still have the option of releasing it for free, too, and I'm weighing that. As a promotional device for the hardcover, it'll probably be more effective as a free download. (And to be honest, judging by the generous tipping around here, I'm not sure I wouldn't make more money that way!) In terms of career outlook, getting those hardcovers sales up is probably the most important thing right now.