Phones are definitely getting bigger. To wit: on the left is the original Droid, measuring 3.7-inches. In the middle the Droid 2 also has a 3.7-inch screen, but a larger bezel. And on the right? That's a leaked photo of the Motorola Droid 3 (or so it's believed), showing a 4-inch screen.
There's some confusion over whether this is the Droid 3 or another Motorola handset, code-named Targa, which we've seen before. The spare parts website that showed this photo called it the Droid 3, but mentions the Targa name also, which is—and correct me if I'm wrong here, folks—the code-name for the Bionic handset.
Whatever it is, the fact that spare parts for either the Droid 3 or Bionic are showing up online suggests that Motorola's readying this handset for launch anytime now. [Global Direct Parts via Phandroid via Droid-Life via BGR]
UPDATE: Commenter Fryhole directed me to PhoneArena's explanation on the Targa, which you can read over here.