This is especially interesting, given many of their international users were hosed when they logged in and found out Bing doesn't have maps for their countries. This is obviously a management move that was not thoroughly thought out and it shows you cannot blindly make changes without incurring some serious wrath of your users.
Would be interesting to know what motivated them to do so.
There used to be talk of Microsoft buying Garmin back in 2007. Maybe this is related?