In the basic scenario in which part A has a dependency on part B, and both part A and part B have methods with [OnImportsSatisfied] attributes, the method in part A is called before that in part B. This is completely wrong as part A's imports aren't satisfied
until part B is ready. And until part B's [OnImportsSatisfied] method is called, it isn't ready. The older version of MEF (System.ComponentModel.Composition) included with Visual Studio handles this correctly on the other hand.
From C (as C has no dependencies)
From B (as C, B's only dependency, is now resolved)
From A (as B, A's only dependency, is now resolved)
From A (wrong as B has not yet resolved)
From B (wrong as C has not yet resolved)