Admittedly I have been very annoyed with Dreamhost since they announced that users would no longer be able to use procmail.
How to get procmail Back
After reading the most recent entry I realized that it is possible to still use both procmail and spamassassin. However, this solution is not elegant.
Currently Dreamhost has a rudimentary Mail Filter system that is accessible by all mail users. This system is due to be upgraded soon. Dreamhost also allows regular shell users to access and run procmail as well as spamassassin. In fact, shell users can install their own custom install of spamassassin. Lastly, shell users can also receive email, although there is no imap or pop service for this mail.