Hi shawn00m, I understand your concern. I also checked in the past and saw that the plugin had not been updated for a while. However since the developer keeps answering questions from time to time and there are 9 users that say it works with WordPress 3.5.1 including myself, I just keep using it. I also check the support Thread and see that many keep contributing to the support of this great plugin.
I am also aware that the developer probably feels that there is no need to update the plugin since it still works well in most environments. I have also tested this plugin with WordPress 3.6 alpha and it works.
I hope this helps you with your concern.