Google Maps 5.0 brings a couple major features; 3D interaction and offline reliability. I immediately made the update on my new Samsung Galaxy Tab and the experience on a large 7 inch tablet display is awesome. The 3D mapping is what you have seen on the website and is great to now have on your phone or Android tablet since it helps give you some perspective as you walk around cities. Google uses vector graphics to draw the map on your device as you use it so you can tilt, rotate, and zoom with different finger movements.
One of the main issues with using Google Maps has been the fact that you needed a connection to use it. They now offer some offline reliability by downloading the areas where you travel often. For example, since I live, work, and play in the Puget Sound, Washington area Google will download these maps so that I can navigate even if I lose signal. It will perform this update when you plug in and connect via WiFi (such as at night while you sleep).
Google is also rolling out offline rerouting support when you use Google Maps Navigation beta. The 3D and offline features require you to have Android 2.0+ devices and I can attest to the fact that it works very well on a Samsung Galaxy Tab.