There is another "Virus" in the wild for Apple's OSX. This one comes in the form of a Trojan that has been placed inside a pirated version of the iWork 09 suite.
The "virus" called OSX.Trojan.iServices.A and once installed has root control over the system.
Intego is rating this as a serious threat, as of now the only way to be rid of the "Virus" is to reformat the system. There is also news of a way to inject malicious code into the Resident Memory in OSX.
In case you are wondering why I am using "" around the word Virus it is due to the fact that when Apple was contacted about this they responded saying this can't be a virus because Macs cannot get them.