Measuring Namespace Complexity

One of the nice things about the .NET Framework (particularly vs. Win32) was its discoverability. There were 108 namespaces and about 3,800 types. There were just a few top-level namespaces and really only a few you needed to think about (System.Web, System.Windows, System.Data, etc.). As we move forward toward the Whidbey release and the WinFX/Longhorn release, we're adding functionality and consequently adding types -- Whidbey may have something like 7,000 types. So how do we balance functionality and namespaces? How many top-level and second-level namespaces should we have? How many members per type? How many types per namespace?