That's detailed in the blog post I was linking to above: http://blog.cloudflare.com/google-now-factoring-https-suppor...

To quote it: "Second, at CloudFlare we've cleared one of the last major technical hurdle before making SSL available for every one of our customers -- even free customers. We're on track to roll out SSL for all CloudFlare customers by mid-October."

I didn't think I could love Cloudflare any more than I already did.