Also see Eric Schmidt’s long-term perspective on the network computer’s “epic journey”
But after spending a few days with the CR-48, I don't think Microsoft has much to worry about yet. If anything, Chrome is more likely to challenge Apple's iOS software used in the iPad.
Chrome OS is elegantly designed with clever features that make it simple to run. But the software is crippled by Google's ambitious business objectives and quixotic pursuit of "online only" computing.