It seems that the malware developers are getting there. Slowly.

More and more it seems that they are starting to target the Apple OS, OS X.

Does this mean that OS X is going to start being targeted like Windows? Probably. Wouldn't be a bad thing either.

http://www.beskerming.com/commentary/2007/07/18/222/A_Worm_for_Your_Apple

Granted, this is only a proof of concept - so far.