The question is whether using SpamAssassin and other tools and blacklist which were made for email spam would really help with web spam. The two are quite different beasts with their own rules and characteristics.
Theoretically, it should be possible to write Spam-X modules to make use of those blacklists.
I assume you saw the post about the
SLV module that will ship with Geeklog 1.4.1?
bye, Dirk