To the extent that anyone was using the Socialcast work media tool to post into the Twitter stream, they won’t be any longer:
Twitter Compatible API: The Socialcast Twitter Compatible API allowed people to view a Socialcast stream, and post updates from within various Twitter Clients such as TweetDeck. On August 30, 2010, Twitter changed their approach and modified their Terms of Service. Twitter now requires that client developers adhere to “third party content” guidelines that drastically limit the ability for Twitter Clients to consume content from services like Socialcast. Due to these changes to Twitter’s Terms of Service, Socialcast will cease support for the Socialcast Twitter Compatible API on October 1, 2012.
Note: The Twitter Feed import capability is not affected by this change.
Basically, Twitter thinks it owns everything that anyone puts into the stream, and it has to stay there. Period.
This is almost as crazy as blocking IFTTT.