Integration of PostgresSQL and MongoDB: Any Foreign Data Wrappers (SQL/MED)?

Hi,

Does someone have experiences with the integration of Postgres and MongoDB ?
And is anybody working on an optimized Foreign Data Wrapper (SQL/MED)
for MongoDB ?

Background: While investigating this, I was happy to find others
mentioning on how the new SQL/MED functionality of PG 9.1 could enable
access to MongoDB. Jim Mlodgenski mentions this feature in the first
issue of the "PostgreSQL Magazine" (http://pgmag.org/ > Issue #00).
And Joshua Drake wrote a blog entitled "MongoDB at PgEast.... say
what?" where he proposes: "Consider, what if our upcoming SQL/MED
support in 9.1 had a foreign data wrapper that was optimized for
MongoDB?" (http://bit.ly/eUStSw ). Now looking at
http://wiki.postgresql.org/wiki/Foreign_data_wrappers MongoDB isn't
mentioned there.

Yours, Stefan