Here's part of the official press release:
Part of the GALAXY S4 family, the GALAXY S4 zoom is the realization of Samsung's mission to create a single device that can fulfill the role of both an industry leading smartphone and a high-end compact camera. Combining 10x Optical Zoom, 16 Mega Pixel CMOS Sensor, OIS and Xenon Flash with the very latest Samsung GALAXY S4 technology, the GALAXY S4 zoom sets new standards for perfect mobile photography. It is the ultimate smartphone and camera experience in one, and the only device you'll ever need.
The Zoom Ring also revolutionizes conventional camera zoom controls. Optical zoom control replaces traditional dials and buttons with smooth, easy-to-operate digital controls. Professional-quality accuracy and unprecedented ease of use are just a twist away, making it easy to compose a scene and capture wide-angle shots or tight close-ups.
When it comes to high quality photography, bigger isn't always better. The compact GALAXY S4 zoom's best-in-class 10x Optical Zoom and 16MP BSI CMOS Sensor lets you capture beautiful images from far away or up close and personal, in all light conditions, without having to carry heavy camera gear around with you. Furthermore, the built-in Optical Image Stabilizer (OIS) helps keep the camera perfectly still even when you're not, reducing blur and stabilizing the image while zoomed in for high-quality photos and video.
Interesting stuff - the size of the sensor in the S4 zoom isn't mentioned, but I suspect it's 1/2.3" and a lot smaller than the 1/1.2" unit in the Nokia 808 PureView and rumoured to be in the Nokia EOS. (1/2.3" was the size of the sensor in Nokia's 2009 S60 3rd Edition-running N86.) The combination of true optical zoom and optical image stabilisation is welcome, of course, the two technologies do rather go together. Though note that Nokia's software zoom system from the 41 megapixel sensor in their flagship PureView devices does have the advantage that it's less bulky and doesn't restrict light ingress, unlike optical zoom systems, which only really work well in good light conditions.
The most debate will centre around the physical form though. Here's the Galaxy S4 zoom in side profile:
...and here's the S4 zoom with the camera activated and the zoom in use:
Samsung is clearly aiming for the Galaxy S4 zoom being considered more of a camera than a phone, whereas Nokia's 808 PureView and (again, rumoured) EOS are clearly just as much a smartphone, at least in form factor and feel in the hand.
I'm torn with this device. On the one hand I'm glad to see Xenon flash and optical zoom back in phones, on the other hand I do rather think that the camera here sticks out like a sore thumb - almost literally.
Just for comparison, here are the sculpted and massively more gentle camera humps of the Nokia 808 PureView (from 2012) and N8 (from 2010):