Can I use ClickOnce to deploy applications today?
No, but you can play with it. Runtime support for ClickOnce requires a new version of the .NET Framework, which is included in the “Longhorn” SDK that’s available to MSDN subscribers. Extended client side support for ClickOnce will be included in the next version of Windows, code named “Longhorn”. A preview of “Longhorn” is also available to MSDN subscribers.