I honestly have no idea when this was announced, but Twitter will start disabling its “Basic Auth” on Aug. 16, 2010 (the system will be completely unavailable by Aug. 31). For Twitter users, this doesn’t really mean anything. However, for Web developers that use various interfaces and plug-ins to share information on Twitter, this is big.
The majority of API libraries and classes that were (and, as of this writing, still are) listed in the official Twitter API documentation will stop working. This change, as far as I can tell, will effect the way tweets are sent and the way tweets are received. Therefore, whether you’re trying to post tweets from an external source, or you’re simply trying to list your latest tweets, if the interface uses the old system of Basic Auth, it’s going to stop working on Aug. 31.