I try to do all my browsing without a mouse and use a plugin called vimperator to manage this. It works great, however I can't logout out of WordPress, because the logout link is hidden in a box which appears on hovering over my avatar in the top-right.
I can focus the avatar and otherwise get to it, but because the div containing the logout link only appears on hover (using css :hover) it is impossible to get to the logout link without a mouse. In fact the whole admin bar become unusable without a mouse. This is a really poor design choice on the part of WordPress and particularly dissapointing for what is otherwise such fantastic software.
Can this please be fixed in another release? Either also use css :focus to make the option appear or open the options through a click (facebook and google both use this approach). The same is true for the left hand menu, but here it is not so drastic because clicking on the main menu item reloads the page with the sub items displayed.