Logging VACUUM activity in version 7.3

Does version 7.3 provide a way to get VACUUM activity reports in the server
log (postmaster's stderr) without having them show up in the client's
stderr?

In 7.2, running vacuum "quiet", i.e.,
/usr/local/pgsql/bin/vacuumdb -U postgres -q -a -z

logged vacuum activity to the server log. e.g.,
"DEBUG:  Pages 0: Changed 0, Empty 0; Tup 0: Vac 0, Keep 0, UnUsed 0.
        Total CPU 0.00s/0.00u sec elapsed 0.00 sec."
without sending the information to psql's stderr or stdout

In 7.3, running vacuum "quiet", i.e.,
/usr/local/pgsql/bin/vacuumdb -U postgres -q -a -z
does not put VACUUM activity reports in the server log

whereas running vacuum "verbose", i.e.,
/usr/local/pgsql/bin/vacuumdb -U postgres -v -a -z
puts the vacuum activity in the logs, e.g.:
INFO:  Pages 0: Changed 0, Empty 0; Tup 0: Vac 0, Keep 0, UnUsed 0.
        Total CPU 0.00s/0.00u sec elapsed 0.00 sec.
but it also sends these messages to the client's stderr

I've modified postgresql.conf to include
"server_min_messages = info"
(assuming that the log prefix denotes the message level), while leaving
client_min_messages at the default, but this doesn't reproduce the version
7.2 behavior.

Help,
    Murthy