At long last, I can finally report that The Two Empires has been submitted to the Kindle Store and iBookstore, and is currently awaiting approval in advance of tomorrow's launch.
The Kindle Store was actually remarkably straightforward. The iBookstore, however, proved less so, when the iTunes Producer software you are required to use threw up dozens of unintelligible error messages at the point it was supposed to be uploading to iTunes. To cut a long and extremely profanity-strewn story short, the solution turned out to be removing the space from the file name of the original manuscript, rebuilding the ebook and then running it through a command-line java tool helpfully provided by another author's blog (serious thanks to Karl Pfeiffer and his friend for making it available!).
Now it's a waiting game. Rest assured that I'll let you know once the ebook is actually on sale, which should hopefully be the early hours of tomorrow if Amazon's estimates are correct.
Bonus: I've updated the sample chapters to Edition 1.2, which is the same as what will be going on sale and fixes a few typos that have come to light since I put the samples up originally. You'd think that between the dozen or so times I've read the manuscript, and all the other people who have read it, all of the errors would have been spotted. You'd be wrong. Rest assured that if any more do emerge, you'll be able to update your purchased versions to the latest edition.
Watch this space!