Apple has released another Beta version of their upcoming iOS 4.2 firmware. The iOS 4.2 Beta 3 supports iPod Touch 2G, iPod Touch 3G, iPod Touch 4G, iPhone 3G, iPhone 3GS, iPhone 4 and iPad.
The Beta firmware is available for developers only! The final version of iOS 4.2 will be released in next few weeks. As far as jailbreaking is concerned, Limera1n and GreenPois0n will not support the Beta version of iOS 4.2.
You can download the Beta firmware from following link.