Google’s Andy Rubin appeared at the All Things Digital conference to show off a prototype tablet computer from Motorola. It runs a new version Google’s Android software, nicknamed Honeycomb and due out next year. Rubin boasted that the new tablet has no buttons, as opposed to the Apple iPad’s apparently burdensome single button. He also test drove a new 3D version of Google Maps for tablets and smart phones. So how does Gingerbread fit in? That’s the newly-released public version of Android, the one you’ll have to make do with until the sweeter Honeycomb arrives.