Seems to me any vendor that wants a chunk of the soon-to-be growing Apple anti-malware market doesn't have much to worry about for now. According to Intego, Apple's anti-malware only scans for two Trojans. Now, I'm sure Apple will add more, over time, but it indicates modest ambitions at best. Second, the scanning feature only evalutes a small number of applications: namely Safari, Firefox, Mail iChar, and Entourage (for anyone masochistic enough to use that application). Intego's overview can be viewed here.
Why not a peep from Apple about this security feature? Probably because viruses don't exist on Macs (don't you know):
And here's a more recent advisement that touts the lack of viruses on the Mac.
Highlighting the addition of anti-malware capabilities would obviously burst the fantasy that OS X is immune to malware.
If you're interested in my mobile security and technology observations, I can be followed on Twitter.