Microsoft has just released Windows Installer v3.1 (MSI3.1) RC1 to testers through Betaplace.
Windows Installer v3.1 is a minor update to Windows Installer 3.0 released in September 2004. It contains new and enhanced functionality and addresses some issues found in the 3.0 release. Members enrolled in the official beta program can visit Betaplace to download their evaluation copy.