They do: a nice two-piece affair. The inner layer is some rubberized material and the outer is a hard shell. It's the same sort of combination you'll find on "active" cases to protect from both shock and impact. The screen is completely open, though there is enough of a rise from the bumper that you won't rest the phone on the screen if it's face down. I would say that a small portion of the rear (no more than 5%) is covered. You certainly are able to show off the colour of the device if you're taking or otherwise have it so that the rear is on display.
From what I gather, there are three colour choices (inner/outer): red/black (I have this on my red 920), blue/white ir pink/white (my wife has this on her cyan 920). I bought these in store, but they are also in the AT&T web site. I haven't seen them on the Belkin site, though.