What about:
ALTER [OBJECT] RENAME TO [schema.]name [CASCADE]
This has somewhat less new syntax.
CASCADE would also move dependant objects.
Perhaps trigger functions should not be moved, since it
is not really obvious how to do this right.
Warning should be issued in this case.
Command basically frees user from having to hack system
castalogs; Is moving dependant object really such a big deal?
PostgreSQL does not really care where they are and just
keeps working - maybe this should be left up to DBA.