I just met with Erik Jorgensen of MSN, and Windows Live Local is going live today/tonight.
A number of features make it interesting and different from what's out there, including personalization, ease of use (I can insert a "pushpin" with my cursor rather than entering an address or landmark) and, of course, the Pictometry "bird's-eye" photography. Right now that only covers about 25 percent of the market (U.S. metro areas). But eventually it will be national and international.
There's a chat feature (two people can be on IM and in the same map simultaneously), which is really cool. And the ability to create specialized/personalized maps (e.g., "Italian restaurants New York," "places to go with kids in Seattle") and save/share those is very useful and valuable. Now everyone can be a mashups publisher.
Look for it at http://local.live.com.