This plugin by DeannaS and kgraeme allows the site administrator to set the defaults for all new blogs created on server.
Installation : Place the cets_blog_defaults.php file in the wp-content/mu-plugins folder. Go to site admin -> new blog defaults and configure new blog defaults. Blogs created after settings are saved will use new blog defaults.
Plugin does the following:
Adds a new submenu to the site admin screen called “New Blog Defaults.”
Allows the site administrator to visual set defaults for each of the major blog sections:
General Settings
Writing Settings
Reading Settings
Discussion Settings
Privacty Settings
Permalinks
Miscellaneous Settings
Theme
Bonus Settings
Download: http://wordpress.org/extend/plugins/wpmu-new-blog-defaults/installation/