It's up. Go check it out. I'm just now looking at it myself.
The ebookstore is live, and it boasts more than 3 million titles.
It looks like those rumors about indie booksellers were true. Google is reporting that you can buy GE from any number of partner bookstores, but unfortunately, there aren't any ebookstores listed yet. I'm sure that was an oversight.
It has the browser reading app (we already knew about), but there is also an Android app and a couple iOS apps (which aren't in the app store just yet). I haven't tried it yet, but you can also transfer ebooks to any ereader using Adobe DE DRM (format support includes Epub and PDF). Now that was a smart move.
Interesting. GE is integrated into your existing Google Books bookshelf. I'm pleased but not surprised. From the back end details I found a couple months back I thought this would happen. I think I'm wrong here.
Update: It's only open to US residents (duh) and you have to have a Google account (duh). There's no real customer service, but we knew that was going to happen. Google sucks at providing real service and support.
Second Update: Check out the known issues page. Don't you just love how Google does beta launches?
So what do I think? I'm a little surprised that Google is planning to compete on the open market. I had thought they would cut themselves off (like Amazon or B&N). All of a sudden the ebook market got very interesting.
Oh, and we're going to see a jump in reported ebook sales for December.