It's a pretty interesting read if you're into that type of thing, and yes, we did just give you permission to try and split your Droid display wide open in a moment of frustration.
The concept in question is quite simple: a primary LCD would be visible at all times, and when the occasion called for another panel or two, they'd simply slide into view, ready to serve as a number pad, or settings control, predictive text display, or even a full-fledged split keyboard.