Today I found an article, that Mozilla released a new project which aims to bring web apps to the desktop. The code name for the new project is Prism.
… a XULRunner based application that allows to run single web applications in an isolated environment without all the navigation, configuration and much other user interface browsers typically feature.
The project is based on WebRunner which is stripped version of the browser. With Prism will be possible to create a Desktop look and feel applications from a regular web based apps.