Is there no one DI/F to rule them all? If we have several DI/Fs will they compose? Is this a sustainable path?
Like anything I think its probably a good and realistic thing that there isn't a single great one, windsor is pretty solid though.. but it focuses more on the ioc aspects.. in terms of raw dependency injection.. ie- I have a service A, which requires service
B.. then MEF is offers more choices of resolution aspects.
You could well today use both mef and something like windsor but I don't think they would align exactly.. I think that MEF may gain more ioc like features in upcoming releases, and become something close to a 'fantastic all rounder' for awhile.
These days I use windsor, but I don't really think any ioc frameworks are really meeting a modern requirement.. mef has stable composition which I think should be something iocs should look into providing as an option.