Google have just recently launched Google MapsGL. Google MapsGL takes the normal Google Maps and uses the power of Web Graphics Library (WebGL) to create far richer visuals and animations. WebGL is a new technology that uses hardware-accelerated 3D graphics and brings them into the browser without the need for additional installed software. With WebGL your maps experience is much better with 3D buildings, smoother transitions between imagery and the ability to instantly "swoop" into Street View, all without a plugin.
Google Maps with WebGL is currently working on just supported browsers (Chrome 14+ or Firefox Beta) with compatible video cards, you'll have to opt in to the early beta release, though. Visit maps.google.com and click "Try it now," or visit maps.google.com/gl to learn more. WebGL has been used to create experiences like their Chrome experiment "3 Dreams of Black" and "All is Not Lost", which is all happening within the browser.
Previously, such sophisticated 3D graphics have only been possible on traditional desktop applications and require a manual installation. WebGL ushers in a whole new generation of graphics on the web, and with that, Google can begin to redefine the expectations of an online map.