More generally, I have never understood why people use these third party CDNs for important sites. Don't get me wrong, I understand the bullet points that the Microsoft's and Google's trot out: User more likely to have it cached, more simultaneously open connections since it's a different domain, perhaps less latency etc. But the simple fact of the matter is if the CDN goes down, your site essentially goes down. Ever…
I think the idea is that hosts like Google (and ostensibly, Mircosoft) are going to have availability that far exceeds your run-of-the-mill website. Those big hosts generally are going to provide five 9's (or more) availability, whereas %your_random_site% is probably going to be on the order of three to four 9's, at best. So more often than not, the point of failure is going to be your website...not the CDN.
If you have the infrastructure ($$$) to support your own web services on the order of 99.999%+, then by all means host it yourself, otherwise you're most likely never going to have a problem with it (especially if you include a fallback method).