your Wrong b/c Microsoft license most there maps from Navteq for Bing for both desktop and WP which is a Nokia owned company.
check bottom right corner.
Bing Maps - driving and transit directions, routes, traffic conditions
Navteq - Wikipedia, the free encyclopedia
If you want to split hairs, then be aware that, that is map data, and that is not the same as "powering", which is the routing and navigation algorithm. That is like saying that Navtech is powering the navigation on my BMW and Porsche. That simply isn't true, the map data is Navtech, but that's it. Becker (Harman-Kardon) is responsible for the software that uses that map data.
And, as far as I know, there are only 2 major map data suppliers, Navtech and TeleAtlas. All the GPS systems TomTom, Garmin, and auto OEM will use either Navtech and TeleAtlas map data, but that's it.
European maps are 3.10GB and US is 1.72GB.
There is many more streets in Europe and more built up areas even though land mass is smaller.
The Navtech map data for my BMW is on 2 DVD's, well more than 1.72GB. The Navtech map data for my Porsche is on 8 CD's, also well more than 1.72GB. The map data not only contain road data, but also POI data.
btw i have a N900 ovi maps on it was terrible unless you install the mod that allows lot of the missing features Maemo5 version never got cared much for by Nokia
Sounds interesting, but navigation on my N900 (and previous N97) just sucks, and that is because the GPS isn't accurate. My position would flip between service roads, the opposite road, and side road, causing frantic and confusing re-routing. It sucked so bad, that I gave up and bought cars with factory navigation. I only use navigation on my phones if I am a passenger in a vehicle now.
I have much more info (about Nokia and Microsoft), but can not share.
Michael.