SpamAssassin finally placed 3.0 into the stable branch. I have upgraded from 2.64 to 3.0.0. So far all is well.
Some spam possibly made it through the system while it was being upgraded (I got TWO) so please don't panic, it's back doing it's job. The individual journal updates and db sync took a lot longer than expected.
Please let me know if you encounter anything abnormal.