I thought Microsoft had the market cornered on terrible product naming but "Googlebook" is extremely awful.
My suggestion, if they really want to go this route, is to shorten it to "gBook".
The first thing that came to mind is "What about all that gobbledygook in your Google-dee-book?"
I'm imagining poultry running around clucking: "gBook! gBook! gBAWK!"
I am old enough to remember that iPad was supposed to be a product-line-dooming bad name.