Mozilla has released the Firefox 3.0 beta 1, it is available for Windows, Linux and Mac.
As Mozilla release notes states it is for testing purposes and aimed at developers, not recommended for normal users.
“Firefox 3 has been built on top of this new platform resulting in a more secure, easier to use, more personal product with a lot under the hood to offer website and Firefox add-on developers.”
Firefox 3 Beta 1 is available in 20 languages

I’m not going to try it anyways, will wait for a stable version.
@Nirmal
i also wait for the stable version
I tried it, and even wrote a review on my blog
Vast improvements in some areas.
I tried it and most the addons are not working on it.