One of the neat things about the new sense UX that will be implemented in the Desire HD is its new map application that has been built in. The difference between this map and the ones of other smart phones is that this one allows for offline use. This, ofcourse, can be extremely useful, with regard to those times when you need directions or a map the most, but it is not avaliable to you (i.e. out of service range, no wifi, etc). With the new app that will be built in (and free) on the Desire HD, this will however no longer be a problem, since offline viewing has been added. In my honest opinion, this is one of the deal breakers that make the Desire HD just that much better than other alternatives at the moment (for example IPhone 4).
Here is a short overview of the map application. Keep in mind that it is in the beta stage and is still in development, so it does not run perfectly. The Desire HD rom has been ported to an older HD2 in this video, and that phone is used for the demonstration:
