Several comments on multiple sites claim that the exploits have
not been seen in the wild and that
no one has been infected but that the various methods of utilizing the exploit have been in discussion on some hacker sites... including the suggestion of a poker game trojan and they have been trading Applescript files that appear to, perhaps, use the method.
It appears that these may be more "proof-of-concept" trojans—based on the ARDagent vulnerability than actual in-the-wild threats.
Defeating the possibility of infection appears to be easy.