Microsoft Windows Search desktop search tool 4.0 is out of beta.
The desktop program, which had been released as a public beta in March, was posted Tuesday to the Microsoft Download Center with different versions for a variety of MS operating systems.
Details on the new Windows Search (with download links) can be found in the Knowledge Base article here.
Other Microsoft releases this week included a new version on Microsoft Installer (Version 4.5) and Windows Server 2008 VHD's.
For those that have been asking, it appears more-than-likely that the next public beta of Internet Explorer 8 will be forthcoming in the third quarter of this year.