Local & Cloud Synergy
I am sure that we can all agree that more and more work is being done on-line and in somebody's cloud but I think that a computer that abandons local storage will find it's place as a user's web browsing, hobby computer.
In my oppinion, MS has the better idea with Silverlight 3's Out of Browser capabilities. This allows users to work online in a high-powered web application (because Silverlight is capable of creating amazing web apps) and also install the web app on their laptop or pc. With the app installed on the users computer, they are able to perform their task and Silverlight, being able to detect network connectivity, will store the data locally untill an internet connection has been found in which case it will synchronize the changes, allowing for conflict resolution.
In my opinion (as well as MS), this fits the business model much better than a dumb internet terminal.