Apple just released iOS 4.2 Beta to developers. As 9 to 5 Mac noted, it’s not only available for iPhones as you can also download iOS 4.2 Beta for iPad, which will bring over-the-air printing.

As usual when a new firmware comes out, it is recommended that jailbreakers and unlockers stay away from it if they don’t want to lose the ability to jailbreak/unlock in the future…

The official iOS 4.2 release is scheduled for November for both the iPhone and the iPad. You can download iOS 4.2 beta from here, assuming you have a developer account.