It's necessary now and it probably always will be. I looked at the installation documents and under section 5.2 of the install document it says:
5.2 Compiling the PostgreSQL driver for AOLserver
Get the enhanced PostgreSQL driver from http://acspg.benadida.com/sdm
Edit the Makefile to include the correct path to your PostgreSQL and AOLserver directories. If you are using the RPM version of PostgreSQL, make sure you have the devel package installed as well.
Do a make and copy the newly created file postgres.so to the AOLserver's bin directory.
If you are running PG 7, make a symbolic link from libpq.so.2.0 pointing to libpq.so.2.1 because AOLserver looks for libpq.so.2.0 when loading the driver.
cd /usr/local/pgsql/lib
ln -s libpq.so.2.1 libpq.so.2.0 (as postgres)
