Courier is a real device, and we've heard that it's in the "late prototype" stage of development. It's not a tablet, it's a booklet. The dual 7-inch (or so) screens are multitouch, and designed for writing, flicking and drawing with a stylus, in addition to fingers. They're connected by a hinge that holds a single iPhone-esque home button. Statuses, like wireless signal and battery life, are displayed along the rim of one of the screens. On the back cover is a camera, and it might charge through an inductive pad, like the Palm Touchstone charging dock for Pre.
http://gizmodo.com/5365299