Yes, they're serious. I was at MBZ for lunch 2 weeks ago, and saw in the parking lot an S400CDI, S270CDI, Brand-new unbadged E-class CDI, a few current E270CDIs and a few others (also saw 2 745i BMWs...probably there to make them feel even better about MBZ styling). Also saw the 1 and only SL55 AMG that's stateside. Woah. Also saw a G55, G500 sport. And as usual, not another 500E in sight
The gentleman in charge of the Corporate motor pool took me out in an SL500-at speed it was quite comfortable and we could converse in normal tones with the roof stowed. And ABC on that car is unreal-made my 500E feel sloppy, no lie

Boy could that guy drive!
I want one, but will wait for the 55