Integration of policyd-weight (
http://www.policyd-weight.org/ ) into postfix would be great.
The big advantig of policyd-weight is that arround 80% of the spam gets bounced even before delivery, so allot recources are safed on the local system.
The other big advantage is that the sender has now the problem with the mail he was not able to deliver (he get's a clear error message, why the mail was not accepted). With spamassassin the recipient has to deal with the spam which is not the best sollution.
regards
andreas