Unity, and Ubuntu Light is a post from Mark Shuttleworth, describing the future of Ubuntu as a netbook and light web browsing operating system.
A few months ago we took on the challenge of building a version of Ubuntu for the dual-boot, instant-on market. We wanted to be surfing the web in under 10 seconds, and give people a fantastic web experience. We also wanted it to be possible to upgrade from that limited usage model to a full desktop.
He continues to talk about touch being a target input for this OS, so making it easy to navigate, changing applications with the touch of a finger has added to the design decisions.