The 911 Modernization and Public Safety Act was passed by the U.S. House of Representatives on Tuesday. If enacted into law, this would require VoIP providers to offer enhanced 911 (E911) service. It would also make it easier for those companies to gain access to the 911 networks that are often controlled by the large telephone companies.
More details here:
PC World – Business Center: Congress Working to Improve VoIP 911 Service