Ok so this rattled my brain a little today as I was installing ColdFusion 10 on my new Mac Mini Server using the new OS X Mountain Lion Server (Registered developer - I have the Gold Master Release). Well, when I would try to configure the connector, apparently OS X Server does not use the default /etc/apache/httpd.config instead this is located in /Library/Server/Web/Config/apache2/ and the default file is not httpd.conf even though it is in there, instead it is httpd_server_app.conf.
So real simple add your reference to the mod_jk.conf to :
/Library/Server/Web/Config/apache2/ httpd_server_app.conf
And then you are Golden - CF10 up and running!