As of v. 7.8, Logos Bible Software supports reopening closed tabs both via panel menus and keyboard shortcuts (PC: Ctrl + Shift + T, Mac: Cmd + Shift + T). Conveniently at least for PC users—and I suspect also for Mac (?), the keyboard shortcut is the same one that will revive tabs in major browsers like Google Chrome.
For additional details and a walk through of how to access this feature through the panel menu see the LogosTalk blog.
There are plenty of other explanations for the dampening of Google’s ardor [for Google Books]: The bad taste left from the lawsuits. The rise of shiny and exciting new ventures with more immediate payoffs. And also: the dawning realization that Scanning All The Books, however useful, might not change the world in any fundamental way.
But, interesting possibilities definitely remain on the horizon. While it remains to be seen what of those materialize, Google Books still provides a useful tool in its own niche area.