Microsoft announced today the final release of Windows Search 4.0:
Today we released the final version of Windows Search 4.0 to Microsoft Download Center. Windows Search 4.0 updates search in Windows Vista, Windows XP, Windows Server 2003, Windows Server 2008 and Windows Home Server. This release comes after a public Windows Search 4.0 Preview, which was a success thanks to great community participation - with around 300,000 downloads. Since the Preview was released, a number of quality improvements have been made to the product based on feedback provided by the community.
More download packages are available on http://support.microsoft.com/kb/940157.
Windows Search 4.0 will be made available on Windows Update in the future as well.