The next generation of Google Maps for Mobile has been previewed by Google's Andy Rubin while demoingat D: Dive Into Mobile.
The fifth iteration of Google Maps for Mobile will feature an overhauled visual style that is based on vector graphics rather than the flat, bitmap images of the current version. The upshot of this change in graphic architecture is that maps now require much less space for storage and less bandwidth to download. Overall performance of the Google Maps software should be improved, but more importantly, lighter map data requirements makes possible the offline caching of routes. This means that once a route is locked in, users will not need to maintain an internet connection for the duration of the trip, which will make Google Maps navigation much more useful for those of us who stray off of the wireless grid occasionally. Of course, altering the route or choosing a new destination will still require a connection, but small reroutes for a missed turn or two may not.
The other advantage of the vector map data is that Google Maps will now offer 3D building data for over 100 cites. These 3D landmarks can be tilted, rotated, panned, and zoomed with multitouch controls. It's a neat feature that may be useful for users who prefer to navigate visually, but I've alway felt that 3D maps are more eye candy than useful navigation tools.
Google Maps for Mobile 5 will be available for download in the coming days. However, while compatible phones will benefit from the improved performance and possibly map data caching, features such as advanced multitouch controls and 3D rendering may be restricted to handsets with the hardware to support them. Phones that will get the full Maps for Mobile 5 experience include the Samsung Galaxy S, the Motorola Droid, Droid X, Droid 2 and Droid Incredible, the HTC Evo, the Google Nexus S, and T-Mobile G2. (Notably missing from this list is the Google Nexus One.)