There are a number of areas that are inspired by the bigger Mercedes. Up at the front, the headlights have changed from the flowing, curvy units of the current model, to smaller, simpler, scowling shapes. And while Mercedes hid the car's nose well, we can tell that the grille is reshaped and has the wider lower half for a more aggressive appearance. The tail is also covered up fairly well, but the taillights are easy to see, and they have the slim horizontal look of the CLS, rather than the swoopy ones on the current CLA. The trunk area looks broader and smoother, too.
Another interesting aspect is that the CLA appears to be longer and cleaner than the old one, especially in the middle. The front wheels look as though they've been moved ahead a smidgen more, or the A-pillar was pulled back. The added length here gives the car a look more like the bigger, rear-drive Mercedes products. That being said, we still expect the CLA to be offered in front- and all-wheel drive. The fact that the hood and trunk don't seem to drop off as rapidly also contribute to the longer look, and the flanks have fewer creases and curves breaking up the sheetmetal.
We haven't heard much about the next-generation CLA-Class, though there has been a report that we'll see an A-Class sedan for the U.S. this year, so a new CLA likely won't be far behind. With that in mind and based on the prototype in the photos, we're estimating roughly another year before we see the production model.