So the ebook is now available, or should be available soon, on lots of different distribution sites. Smashwords claims that they distribute it to outlets such as Apple (distribution to iBookstores in 31 countries), Barnes & Noble, Sony, Kobo, WH Smith in the UK and FNAC (both powered by Kobo), the Diesel eBook Store. This is in addition of course to Smashwords.
And here is the most important bit of information. You can use this voucher to download the book for free: PC23K