At 12:22 pm EST Google reported that they are investigating an issue with Drive, Google+ Hangouts, and Google Talk.
More information will be posted at the Google Apps status Dashboard as it is made available.
12:57 pm EST Update: Google has also listed these issues under the Known Issues of the Google Enterprise Support Center. You can file a case with these issues by clicking on the Me Too button on the Known Issues Page.
4:00 pm EST Update: Google is reporting that the issues with Drive, Hangouts, and Google Talk have been resolved. If you are still seeing these errors please let us know!