What's interesting about this is that the API has been officially deprecated since 2010 (and "offline" since September 2014), but today is the first day that it's actually become unavailable.
Edit: Additionally, there are probably going to be big repercussions to the web/average person's browsing experience as a result of this. A massive number of sites (and programs, bots, etc) were using this API because of its simplicity (and absence of registration/authentication).