I know that some community member been working with the idea for making a “eZ Factory” solution setting up a larger amount of eZ sites within one eZ Publish installation base.
As fare as I remember the conclusion of this were that the manual setup of a new siteaccess were a so small part of the over all job that it wasn't worth the effort to make an automatic system.
If you contact me I can give you contact information to some partners that been building their custom setup solution for new sites.
Best regards,
Egil Fujikawa Nes egil.fujikawa.nes@webdealhosting.com