The Virtual Earth v6.1 Map Control API was released today.  It is reverse compatible with the v6.0 version of the API.  Here's a list of some of the new enhancements:

• Birdseye Hybrid - a new VEMapStyle.BirdseyeHybrid map style which allows you to switch to Birdseye view with the street overlays and labels over the map.  You can also switch to standard Birdseye style to turn the labels off.
• Walking Directions - the GetDirections call now supports a VERouteOptions.RouteMode property which allows you to specify walking or driving directions.
• Traffic-Based Routing - the GetDirections call now supports a VERouteOptions.UseTraffic property to specify if you want to routes to take traffic into consideration
• Reverse Geocoding - a new FindLocations call was added to the map which takes a VELatLong and will return reverse-geocoded places for that location.
• Enhanced Printing Support - a new SetPrintOptions call was added to put the map in a printing mode which significantly improves the printing experience for Virtual Earth across different browsers.
• Improved Browser Support - Includes enhancements to improve the experience on Safari 2 and Safari 3 on the Mac.
• New Navigation Control - Improved navigation control with Aerial and Birdseye with a Labels toggle to turn street labels on and off in both modes.
• Improved 3D Experience - including more detailed textures and improved building models in cities -- currently visible in Las Vegas, Dallas, Phoenix, and Denver.  This will be expanded to future cities later this year.
• Localized Directions - Localized itineraries for driving and walking directions for many locales.
• Localized Navigation control - The navigation control now is localized for many locales

You can find all the latest details in the Virtual Earth Map Control SDK, Version 6.1.  Or you can download the Virtual Earth Map Control SDK (CHM file) directly.  You can also try out the updated Virtual Earth Interactive SDK.