The point is...
that you don't need to rely on a "Real OS" with the cloud. The entire point of the cloud is to make sure that the OS of the end device does not matter. As I have stated before, I think most of the world will rely on the private cloud and not on a public cloud, but even that is irrelevant.
These are the same tired arguments made about File and Print Servers years ago, "but if the server is down I can't access my docs", well guess what that is not much of a problem, networks were built to handle it. The same thing is happening again, this time without the wires, and with more options for access.
Sure for the foreseeable future there will be desktops, but they will blend with tablets. Tablets aren't going anywhere anymore than the desktop is. However, I think the Microsoft OS on the desktop is in trouble long term, and I have read that they know that too.
