This announcement came today on foot of yesterday's news of Google Editions opening its doors in late June/July this year. The news was a little puzzling - a case of stating the obvious - though it is something publishers out there are still extraordinarily casual about. You must assign a unique ISBN number to a book, and that includes an e-book edition, at least if you want to be taken seriously as a digital publisher and want your published books to sell through normal book distribution channels.
Bowker and Google Editions Deal

