In order to get the uninstaller out to the folks that need it now, we've gone ahead and posted the script required here. You can download the shell script or you can cut copy paste from the below it you are more comfortable with that:
#!/bin/sh
# clean up the previous installation so we can test it again.
echo
echo \# This script will attempt to remove all vestiges of a PostgreSQL8 installation
echo \# -----------------------------------------------------------------------------
echo \#
# make sure that we are running as root
x=`whoami | grep root`
if (! test -n "$x") then
echo \# You must be root \(sudo\) to have sufficient rights to remove the
echo \# folders and files that need to be removed.
exit 0
fi
#set -e
echo \# User: $x
# make sure the database is shutdown
echo \# Stopping the Database
/Library/StartupItems/PostgreSQL/PostgreSQL stop
echo \# ...done
# remove the user and group from the netinfo database
echo \# Removing NetInfo entries
PG_UID=`/usr/bin/dscl . -read /users/postgres | grep "^UniqueID:.[0-9]" | sed 's/.*: //' | sed 's/ //'`
# User exists
if test $PG_UID; then
sudo /usr/bin/dscl . -delete /users/postgres
echo \# ...Deleted Postgres User: $PG_UID
fi
PG_GID=`/usr/bin/dscl . -read /groups/postgres | grep "^PrimaryGroupID:.[0-9]" | sed 's/.*: //' | sed 's/ //'`
# Group Exist, destroy it
if test $PG_GID; then
sudo /usr/bin/dscl . -delete /groups/postgres
echo \# ...Deleted Postgres Group: $PG_GID
fi
echo \# ...done
# remove the log files
echo \# Removing Logs \& Receipts
sudo rm -f /Library/Logs/PostgreSQL8.log
sudo rm -rf /Library/Receipts/backupDatabase.pkg
sudo rm -rf /Library/Receipts/cleanInstallation.pkg
sudo rm -rf /Library/Receipts/createDatabase.pkg
sudo rm -rf /Library/Receipts/createUser.pkg
sudo rm -rf /Library/Receipts/pgsqlkit.pkg
sudo rm -rf /Library/Receipts/postgresql.pkg
sudo rm -rf /Library/Receipts/postgresql8.pkg
sudo rm -rf /Library/Receipts/postgresql83603jdbc3.pkg
sudo rm -rf /Library/Receipts/postgresqlServer.pkg
sudo rm -rf /Library/Receipts/queryToolForPostgres.pkg
sudo rm -rf /Library/Receipts/uninstallPostgresqlServer.pkg
echo \# ...done
# remove the directories
echo \# Removing Files and Folders
sudo rm -rf /Library/PostgreSQL8
sudo rm -rf /Library/StartupItems/PostgreSQL
sudo rm -rf /Library/PreferencePanes/PostgreSQL\ Server.prefPane
sudo rm -rf /Applications/PostgreSQL
echo \# ...done
echo \#
echo \# -----------------------------------------------------------------------------
echo \# PostgreSQL8 has been removed from the system.