Microsoft has begun testing the next release of Windows Desktop Search. Unfortunately this version does not include an end-user UI, but the next release is expected to have it. This release is for the Engine Preview ONLY. It allows applications like Outlook 2007 and OneNote 2007 to be indexed so that the content within those applications can be quickly searched.
Here is what Microsoft has to say about this release:
Windows Desktop Search 3.0 enables fast search on your PC using indexing technology. It helps you to find your documents, email, music, photos and other items. The search engine in Windows Desktop Search (WDS) 3.0 is a Windows service that can be used by applications such as Microsoft Office Outlook 2007 and Office OneNote 2007 to index application content and deliver instant results when searching within an application. After you install this item, you may have to restart your computer. This release is an Engine Preview of WDS 3.0 Beta. It contains the WDS 3.0 engine only and is meant to support searching from desktop applications such as Microsoft Office Outlook and OneNote 2007. Since this release does not provide a full desktop search experience, users of earlier versions of Windows Desktop Search should not upgrade to this release unless directed to by Outlook 2007, OneNote 2007 or another application. The next beta release of WDS 3.0 will include end-user UI to allow searching over all indexed content from a single place.