Text Selectivity Operators in String Types

Howdy,

A while back, thanks to feedback from RhodiumToad on #postgresql, I
added selectivity functions to the citext operators:

CREATE OPERATOR = (
LEFTARG = CITEXT,
RIGHTARG = CITEXT,
COMMUTATOR = =,
NEGATOR = <>,
PROCEDURE = citext_eq,
RESTRICT = eqsel,
JOIN = eqjoinsel,
HASHES,
MERGES
);

However, it looks like these might be less than ideal:

http://www.depesz.com/index.php/2008/08/10/waiting-for-84-case-insensitive-text-citext/

From what depesz sees, the eqsel and eqjoinsel functions might be a
bit too aggressive in recommending the use of indexes.

So I was wondering, since in CVS HEAD citext is able to identify its
type category as string, might there also be some way to use the same
estimator functions in the citext operators as are used for text?

Thanks,

David