SNMP MIB for PostgreSQL?

Greetings. I'm looking into to doing some detailed performance
monitoring of a Postgres instance (as a general project, not for a
specific setup). I was inspired to research it after spending some
time setting up the same for Oracle, which has some built-in handling
for MIBs (generic and Oracle-specific), which could be queried by SNMP
and then visualized with applications like MRTG and Cricket. Database
administrators love that stuff. :)

I did some research and it doesn't seem like there's much out there
for Postgres. I saw a thread from earlier this year (Feb-Mar 2001) on
performance monitoring in general, and there was some good discussion,
but I can't tell if anything substantial came out of it. I saw Bruce
Momjian's tcl/tk monitor application, which looks great, but I'm
interested in something with higher granularity and more accessibility
(e.g. via the web).

In any case, I'm wondering if anyone has A) pointers to projects
working on or thinking about this already, B) reasons why it's not a
good idea or not possible, or C) ideas about how to proceed with
creating something useful.

Thanks!
Chris Hardie