Smashwords also maintains a Premium Catalog, which means that properly formatted books will be distributed to many online retailers and libraries, so in the near future my book will also appear on Barnes and Noble, Apple iTunes, and other sites. The nice thing is I have complete control over the price, and royalties are still very good when compared to traditional rates.
Someday I may make a few tweaks and offer as a paperback, we'll see. The book is really meant as a prequel to a planned book or two; I was inspired by the Hiero books by Sterling Lanier from way back when, and he never was able to finish the third book of his series. I've always had a fascination with post-apocalypse stories, but none have captivated me like Lanier's books.
So, someday, I plan on returning to continue the story.. though probably not in the fashion many may expect me to...