It has taken over two years to get to the point we're at now in terms of a critical mass of sites linking to the Google CDN via the HTTP references. I'd have a

It has taken over two years to get to the point we're at now in terms of a critical mass of sites linking to the Google CDN via the HTTP references. I'd have a hard time recommending people begin switching to the SSL reference now (sacrificing that cross-site caching benefit that has accumulated) unless they're actually serving encrypted pages and need to solve the mixed content issue.