The main idea of Dekoh is to bring the best of features on Desktop and Web to end users and developers. Jay in his presentation had a nice slide that captures this.
Here is a brief description:
Universal Data: Applications can blend data on their file system with data on the web (website APIs) in their applications.
Control over sharing: While desktop is a fully private environment, the concept of social web is community based sharing. Dekoh desktop applications can be shared thru Dekoh Network. It is your private network.
Benefits of a hosted application: Desktop applications are self contained and rich in user interface (also easy to install and manage). Deploying and managing web applications is a little geeky job (folks in enterprise software world know this, the reason why SaaS model is becoming popular). Dekoh camouflages all the complexity. Installing and running Dekoh desktop and applications is just a one-click operation. It is totally end consumer usable.
Bringing web 2.0 to desktop: Use your personal media (photos, music, video, blogs, books….) and collaborate with your personal network. Run your web applications on the desktop
End user applications: End consumers can install Dekoh Applications and organize their personal media and share it with their personal network.