Bing Maps provides a robust API to support building pretty much any mapping application you might think of: We used Bing Maps for Subaru's "Get Out More" Site (http://www.subaru.ca/getoutmore) which provided us with the ability to produce a rich Mapping interface for Activities across Canada.

Overall my experience with Bing maps was a positive one. The API was extremely rich and matched up well with functionality provided by Google Maps which I have used previously. I think coming from a .NET background I found the Microsoft Bing Maps API to be more familiar and logical to my .NET experience which helped with the transition.

Some of the features we used on this site build were

Full Map Functionality
Custom Point placement with custom Icons
Geo-location to find address and positions on the map
Jumping to points on the map so users could navigate between search results
Separate layers for different types of content being displayed on the map
Zoom Level Manipulation
Customization of Navigation controls
We Optimized the load of the activities by only loading activities that were viewable within the map and within a minimum zoom level

Used the Map Info API to get the positions of all the corners of the map
Map event handling
Calls to Activate Point Info Boxes
etc

The above features are used in combination with each other to achieve the effects and transitions that we desired.

A great starting point for my investigation was the Bing Maps Interactive SDK demo site which provided example source code of specific features we required for the site. You can find the Interactive SDK here: http://www.microsoft.com/maps/isdk/ajax/

Take a look at the samples and see what you can do!

Mike