It is now acceptable for publicly traded entities to release financial data via social media like Facebook and Twitter, based on this finding by the Security and Exchange Commission. The question came up based on this account of Netflix CEO Reed Hastings running afoul of existing rules by trumpeting Netflix’s membership numbers.
There’s an excellent opportunity for companies who use WordPress as your CMS for your company website. There are several plugins (with Alex Jones’ Social being my favorite) which allow you to easily push all new content out to Twitter and Facebook. This makes it easy to get your news out without having to visit multiple sites and re-posting your content.