This is a very central problem to this kind of trust metrics, people are
rated according to what they do at some point in time, without taking
into account who they relates to and what is they previous history in
other contexts. In the history of the Stave Church article, there is an
archaeologist anyone able to locate the person? I think it should be
possible to identify a person as an expert within a limited field of
expertise, but it isn't easy to figure out how this should be done.

This is what we started the Citizendium project for. Wikipedia maintains a degree of anonymity that forms the basis for one of the many cultures of the WMF projects. If we start verifying qualifications, we throw this all out.

The middle ground is a peer-based "reputation" system, as found on many forums, where for various actions peers can allocate reputation to a user. This type of ad-hoc, informal peer-review is the only way to achieve verification of authority without taking the Citizendium approach.

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Akash