The Palm Pixi has a rubberized, scratch-resistant back cover, so it doesn't feel as slick and plasticky as the Pre. On back, you'll also find the camera lens and flash, but it still doesn't record video.
The Pixi offers a user-replaceable battery but rated battery life wasn't yet revealed. We hope that it'll be better than the Pre's. Also, there's no expansion capabilities, though given the Pixi's intended audience, we think 8GB of internal user storage will be enough for most.