I noticed a post on the Windows Installer team blog this morning that I wanted to link to here.  There will be a beta available soon for Windows Installer 4.5, and the team is asking for folks to sign up to participate in the beta program.

If you're interested in trying out a beta version of Windows Installer 4.5, I encourage you to check out the following locations for more information:

• Announcement on the team blog - http://blogs.msdn.com/windows_installer_team/archive/2007/06/25/windows-installer-4-5-beta-accepting-nominations.aspx
• Sign-up location on the Connect site - https://connect.microsoft.com/programdetails.aspx?ProgramDetailsID=1506