Google Maps is launching a 3D version of their mapping program. It is first launching on Android any day now and then to other mobile devices. Ultimately, I assume it will come to Google Maps on your desktop.
Here is a screen shot from Search Engine Land:
This is using vector imaging and not bitmap tiles. So it requires a lot more CPU processing, but for most modern phones and computers, it should be fine.
Here is a video demo from the Wall Street Journal.
Greg Sterling also added that offline mode is coming. Greg said:
The second major enhancement is offline reliability. The new Maps for Mobile will work without a persistent data connection. It extends to rerouting in Google Navigation, while not connected. And this starts to give Maps for Mobile the persistence of a paper map.
Forum discussion at Google Blogoscoped Forums.