One of our sources was so kind (Thanks!) to send us his first impression about the upcoming new 16-50mm SSM lens! He tested a prototype which is close to production model. Apparently the 16-50mm lens is suffering from slightly corner vignetting and corner softness at f/2.8. It is not too bad at all but just not perfect. The very good news is that at 17mm the lens is is perfect!
As you know the lens is a Sony (not a Zeiss) and it will have a price of 750 Euro ($799 dollars).
Some other source did test the lens and can confirm the quality report made by that source?
UPDATE: The source also said that Sony was (or is?) considering to make it 17-50mm (instead to start with 16mm) to increase the image quality. But the problem could be the fact that there is alreayd an excellent Tamron AF 17-50mm F/2.8 XR for Sony! P.S: Click those links to see the Tamron for Sony: Amazon, B&H, Adorama, eBay.