Personally, I would like to see, or envision the namespaces as being â€˜coreâ€™ vs. â€˜non-coreâ€™
For example, â€˜coreâ€™ for me, System.* represents the namespaces in the .NET framework. When I install the .NET 3.5 framework, I would expect all the namespaces to start with â€˜Systemâ€™ â€“ CLR.
If there are external installs â€“ ie. Silverlight, Ajax Toolkit, even the current ASP.NET MVC â€“ I would expect all those to be â€˜Microsoftâ€™. *If* later they are added to the framework â€“ then it would be System.
ie. since WPF shipped in .NET 3.0 â€“ all itâ€™s namespaces would start with â€˜Systemâ€™ â€“ but since Silverlight is not a part of a framework install â€“ it would be Microsoft.Silverlight
I could then look at my references and clearly see what is a separate install vs. the core framework install.
My current asp.net mvc application would have a System.Web namespace and a Microsoft.Web.Mvc namespace.