Some more criteria that it would be nice to see implemented:

parentLocationRemoteId
subtreebyRemoteId
sectionIdentifier (need 1st to check if there is a unicity constraint in the db table, which it should)

and the more exotic stuff

viewcount (gt, lt, eq)
starrating (gt, lt, eq) => can be done using fieldtype?
infocollection (nr, date of last one)
sorting by viewcount, date of last infocollection, nr of infocollections
sorting by class name, class identifier