Well, now that we have an image, we can do comparisons.
While not a sexy look, it's a very plain black tech look. very easy, symmetrical, intuitive design. While we don't know if it will still make noise, we do know that the PS4 Slim is going for a basic design.
The Xbox one S, while looking a bit more sexy, is going for a stylistic design. this makes sense as the Xbox one needs to boost it sales, so is trying to get the buyers to be attracted toward it with it's white and glossy/matte combo finish.
The PS4 doesn't need that, as it's winning. The PS4 just need s a slick easy visual, streamlined look.
One thing though the PS4 S doesn't seem to have optical out. While the XO has removed the kinect jack, which you need an adapter.
Both take off ports.
My guess is the price of the PS4 Swill be based on the material. if it's a regular material, I expect around a $350 price like the OR PS4. If it's a cheaper plastic, I expect $299.
That's a very good price range to under cut the Xbox one S, although the Xbox one S does have HDR and Blu-ray so it'll be an interesting fight. In NA.
For everywhere else, the streamlined PS$ slim design will likely dominate.