Google Adsense Goes Down For the Count

We're not quiet sure what happened, but appears Google Adsense had gone down for the count. For at least the last 2 hours, users are redirected to the following link:

http://www.google.com/errors/asfe/system_down.html

Could it have been hacked? With the lack of information, many users are wondering what the search engine monster has been subjected to. Although Adsense has gone down in the past, outages lasting for so long are rare.