For me the key aspect of a watch should be how long it lasts. A week on battery seems ideal. If they could somehow add a solar film to the display to keep the battery topped up that would be great. A solar film probably wouldn't be effective for a smartwatch that only lasts a day or two on a charge, but for something that can last a week it might work.
I have no issue with the slower CPU in the Pebble. It's a frickin' watch with a monochrome display.
However they could try and make the next version have a display that stretches to the bezel, and had higher resolution or contrast. And whatever people say, a touch screen, even if it was simple (single finger tap or swipe) would add some interaction possibilities.