Jolla's Sailfish OS has now made first public appearance at Slush conference. I think this video shows quite nicely what the UI is all about:

It took a lot of hard work and determination to get here. At the moment, I'm tired after working long days and then partying hard at Slush. I'm happy and so darn proud of what we have achieved. I know that there is still a long road ahead and a lot to do, but in a very short time we have already achieved a lot. We were able to show pretty impressive UI.

It's amazing what a small, talented, and motivated team can do with right technologies and tools.