Shibboleth Developers

I'm trying to understand the usage of eduPerson attributes in Shibboleth
assertions for inter-institutional applications. It seems that the
attributes that return DNs (such as eduPersonOrgDN, eduPersonOrgUnitDN,
eduPersonPrimaryOrgUnitDN) are not very likely to be useful in this context,
since the directory server that these DNs correspond to is neither specified
in any of these attributes nor very likely to be exposed for direct access
outside the institution. 

In trying to see the usage patterns for attributes being used in various
Shibboleth deployments, the JSTOR and OLCC pilots indicate usage of
eduPersonAffiliation and eduPersonEntitlement. Are there other attributes
from eduPerson, person, inetOrgPerson or organizationalPerson schemas etc.
that are being actively used in applications?

Any thoughts or comments will be appreciated.

-- Vishal