The criticisms I’ve seen on the Google tool tend
to use the a user’s lack of skill as a critique of
the tool itself.

I think that if a site owner is an authority or
subject matter expert with adequate tech skills
as well, she can enhance her users experience in the
following way…

Given that a site has been around awhile offering
content and interacting with a core user group, the owner
should know:
the users demographics, goals and information requirements,
what content they access most,
what sites they arrive from,
where they go when they leave,
the search terms made to get to the site and
the ones they use while there.

With a comprehensive keyword research performed
in addition to what is now known (or inferred)…

I think that owner would have sufficent relevant
queries to run against a meta-engine (Dogpile?)and come up with
a core group of a couple of thousand sites to use as
a foundation for providing the JIT information requirements
of the overwhelming majority of their users.

Users behavior against the core group of sites can be then
used as a basis for expansion.

This, I think, addresses the filtering problem as well
as the base problem of providing a good list of relevant sites.

Admittedly, I only spent 10 minutes working on this so I welcome
any reponses.

I believe Google CSE is not a vertical and should not be categorized as a stand alone search engine.