Microsoft Desktop Search
Above everything that Google Desktop does, MSN's doohickey also searches metadata like Apple's Spotlight (so you could for instance search files by the name of the author, etc.)
Tom Warren has the world-exclusive first public look at the MSN Toolbar Suite. The suite consists of two products, the MSN Toolbar/Deskbar, and MSN Desktop Search.
The MSN Toolbar/Deskbar is a series of toolbars: One for Outlook, one for Internet Explorer / Windows Explorer, plus the MSN Deskbar. The toolbars reside in their respective programs, while the Deskbar goes in the taskbar, much like the Windows Media Player Toolbar, and all of them allow you to search, either based on whatever program you're in, or globally. It integrates fully with Windows, and with Desktop Search.
Unlike Google's product though, Tom says MSN Desktop Search allows you to search for the author of a file which may mean it searches metadata like Apple's Spotlight, which in turn may mean it can search for other metadata items, and Windows does allow for a lot of metadata.
Google Desktop Search landed with a splash, but interest seems to have fizzled, as many realized how limited it is. Speed isn't everything, and like MSN Search to Google Search, MSN Desktop is likely to be comparable in that area. Even one or two extra features is going to give Microsoft a significant edge. Google might want to think about upgrading its product's capabilities, and fast. MSN's is coming next month.