Due to an increasing amount of laws, a lot of corporations are manding that all computers have firewalling, antispyware, and antivirus software installed, be it a Windows machine, or a million dollar multi-node Sun Fire server.
I have not done market research on this, but having a commercially licensed utility for UNIX servers may be profitable, because its not relatively hard to code compared to Windows, and can use a lot of current update code.
For example, one company I worked for had a number of high end Suns for their database servers. They nearly had to sell them off and purchase Windows boxes just because nobody made antispyware for them. Although by design, UNIX boxes are almost immune to malware, installing software for this is mainly for legal assurance reasons rather than technical.
With a generic UNIX based antivirus/antispyware product (firewalling is handled at the kernel level on UNIX variants, so no third party software is needed, other than maybe some for enforcing corporate policies and interface.), I can tick off a checkbox on a legal sheet certifying that every single machine used has a commerical and certified antimalware package installed.