Google/ZDNET Follow ZDNET:  Add us as a preferred source  on Google. ZDNET's key takeaways The new Googlebook looks promising, but questions remain to justify their cost.  Chromebooks had a clearly defined use case that reflected a real consumer need.  The brand I most expected to see was absent from Google's announcement.  Google just announced a new product line: the Googlebook, marketed as the successor to the Chromebook with more capable hardware and a compelling promise: the merging of Android and ChromeOS into something better.  This as-yet unnamed operating system has been cited as "AluminumOS" through various leaks , but has not yet been officially announced by Google.…