Google seems to be rolling out an interesting pack of security updates for their sites. The only official announcement I’ve seen is for Gmail, but I’d expect this to come for many other services.
Currently a lot of Google services work fine with https (docs, calendar, blogger.com) but none seem to offer the same default options that Gmail has. Hopefully that will change soon.
Co-incidentally, it may just have something to do with this recent announcement from their Chief Legal Eagle.