This is the 2018 Mercedes-Benz E-Class Cabriolet, which joins the coupe, wagon, sedan (in E300, E43, and E63 flavors), and the All-Terrain. It's coming to Geneva, so you won't have to wait long to see the rest of it.
Other than what we already know – that this will be the first E-Class convertible to actually ride atop an E-Class platform – there's not much to be gleaned here. The previous model rode on a modified C-Class platform, and prior to that the closest relative was the CLK coupe and convertible (also related to the C-Class). The platform switch is a very good thing, indeed. All the E-Class variants we've driven so far – the E300 sedan, the E400 wagon, and the Mercedes-AMG E43 – have proven that the architecture is wonderful (even if the E43 variant didn't convey a lot of charisma). It'd be a shock if the Cabriolet wasn't par for the course.
Also, that'll round out the E-Class family, so there aren't any esoteric variants waiting in the wings. We should have information about European engine choices and specs in Geneva, with American-market specs to follow sometime after that.