iBooks publishers

Does anyone know whether there is a way to find out which publishers publish or will soon publish e-books for ibooks? If so, could I have a link? I want the ipad's ibooks app to be my primary e-reader but so many publishers are not publishing on this app. It would be great if one could find out when such agreements are to be reached; I'd hate to buy the kindle version only to discover that had I waited, I would have found the desired on the iBooks store soon enough.

If you get an iPad, you also have access to the Kindle bookstore, as well as pretty much every other bookstore. So it's actually the best choice right now as opposed to single bookstore devices like the Kindle and the nook.