Now that fully automated certificate issuance is becoming more mainstream (thanks to Let's Encrypt) I foresee this sort of thing becoming much more common in the future.
Unless I'm misunderstanding they did that by partnering with a CA. Becoming a semi-trusted CA themselves. This is not an option for most organizations.
That was only necessary because, at the time, there was no other way to get a large number of wildcard certs issued for their domain in an automated fashion.
With ACME that will no longer be the case. Let's Encrypt will allow you to do basically the same thing for free with ~20 devices a week[1] starting on February 27[2], for example. In the future, commercial CAs may choose to offer similar services with more relaxed rate limits.