New UI feature: Splittable visualization area
Binjr has had the ability to detach a tab into a new window to allow the user to view more than one worksheet at a time for a while now, and this has proven to be a really useful feature, especially on multi-monitor setups.
But admittedly, it can be a tad fussy to set up when you want to view several worksheets neatly arranged in a grid on a single screen (unless your window manager is able to handle that for you, that is).