ThemeTailors has released a plugin aimed at the users of CloudFlare service who are running a multi-user WordPress blog.
The plugin is named CloudFlare WPMU Plugin and it uses the CloudFlare API to add new blogs (subdomains) to your CloudFlare account automatically.
CloudFlare does not let you add wildcards for subdomains which makes it necessary for you to manually add every new blog (subdomain) to their backend manually. This plugin automates the process.
The free version works for future blogs that are added to the CloudFlare account. A paid version is also available which can add existing blogs to the CloudFlare account.