If you are into 3D maps and used it using Internet Explorer, you should know this. But if you are using firefox, then wait no more, firefox plug-in is also available.

You can check the site here http://virtualearth.spaces.live.com/blog/cns!2BBC66E99FDCDB98!8495.entry

It also have some fixes and updates of the current version release. Some excerpts on their blog.

If you’re running Firefox 1.5 or later or Windows, the VE3D control is now supported. It is a Netscape style plugin developed using NPAPI and hosts the VE3D managed control. In Live Maps, click the 3D button on the navigation dashboard to launch the setup to either install or update 3D functionality. The setup process itself has been streamlined for both IE and Firefox users – It’s a lot smarter about dependency checks and component installation. Regardless of which browser you use, you only need to run the setup once and you’ll be able to go into 3D view in either browser. Memory management and cache performance has been improved in this release of 3D, providing a better overall experience for exploration.

So get it, if you want it. http://virtualearth.spaces.live.com/blog/