Thinking about your discussion late vs early binding:
If the package loading tools were to support compilation (early binding) based upon the definition of the namespace into which the import is occurring then we could stick with early binding being the default rather than accepting the cost of dnu's etc.
I am thinking here of SystemEditor which compiles the new implementation 'off line' so to speak. If System editor can be connected to the namespace SystemDictionary of choice to perform its magic then this could work well.
...
Thinking out load, I am also wondering whether supplying extension methods as a specialized form of trait could also work.
Keith