Like the headline says, Google will officially launch its own e-book store, Google Editions, in June or July. But there's a pretty big catch, according to CNET:
One key difference between Google's approach to digital book sales and the approaches used by Amazon and Apple is that Google customers will not be able to download books sold through the store: they'll be accessible exclusively through a Web browser. That has some advantages for Google, in that it side-steps messy DRM (digital rights management) questions and allows it to offer the service for any device, rather than having to negotiate deals.
This is a weird approach. Part of the whole tablet/e-book explosion of the last year has been about making sure that books are available to their purchasers around the clock, and that the devices have the battery power to sustain long periods of reading. Internet access consumes a lot of power in mobile devices, and it's still not available everywhere. Will people be willing to buy online-only e-books? And how much will they be willing to pay for them?
UPDATE: I just found an Engadget post from last year that says "The books will be available to any device with a web browser, but will be available offline after they've been accessed the first time," which sounds more reasonable. Google is also going to allow bookstores to sell Google Editions through their websites and keep the "bulk of the revenue," providing Google with hundreds of storefronts through which they can sell their books.