Microsoft Released version 2 Beta of Microsoft Security Essentials yesterday (20th July 2010).

New features

Windows Firewall integration: Microsoft Security Essentials setup allows you to turn on Windows Firewall.

Enhanced protection from web-based threats: Microsoft Security Essentials has enhanced integration with Internet Explorer® which helps prevent malicious scripts from running and provides improved protection against web based attacks.

New and improved protection engine: The updated engine offers enhanced detection and cleanup capabilities and better performance.