The fact is that it is not so often when malware for Mac systems come to public.
There is new information about Proof of Concept virus for Macintosh systems available. From the new writeup:
Infects other files when they are executed in the current directory, regardless of file name or extension.
Additionally, the known infection length is 528 bytes, lists Symantec writeup.
The name of this new virus is OSX.Macarena.
Update: The following blog entry of Ryan Russell has a coverage list of recent Mac malware.