The control has Autosuggest so will provide suggestions dynamically as the user types a location in a search box. The streetside imagery is also new, so that you can provide 360 degree spin around showing street view images.
Support has been added for clustering, so where data points are close together, the pushpins showing where the locations are will overlap, and group and ungroup automatically as users change the zoom level. 
A new heatmap display has been added so you can show the density of data points as a heatmap. There's also a new spatial math module with operators that can be used to calculate distances and areas, or for more abstract uses such as performing boolean operations on shapes.
Administrative boundary data is now available, and GeoJSON support has been added making it possible to import and export GeoJSON data.
There's an interactive SDK where you can try out the new features.
Alongside the new version of the map control, Microsoft has released an update to Bing Spatial Data Services (SDS). This lets you upload, host and expose your data as a spatial REST service, so it can be used in any application without having to develop your own custom web service. SDS also supports batch geocoding and reverse geocoding, and provides the ability to access administrative boundary data such as polygons for zip codes, cities, and countries.
The new features in SDS mean you can create custom data sources using KML and Shapefiles. Shapefiles can also be automatically projected into the WGS84 Mercator projection used by Bing Maps, making the data easier to visualize on Bing Maps.