And even before the Jan. 27th Event, where it was expected of Apple to pull the curtains off the iPhone OS 4.0, a screenshot of the OS has been leaked on the web along with some details.

According to BoyGeniusReport, the details about the iPhone OS 4.0 have been leaked through an inside Apple contact. Here are some of the features in the new OS.
- There will be multi-touch gestures OS-wide.
- “A few new ways” to run applications in the background — multitasking.
- Many graphical and UI changes to make navigating through the OS easier and more efficient.
- The update will supposedly be available for only the iPhone 3G and 3GS.
- A brand new syncing ability for the contacts and calendar applications.
This is definitely some very interesting and exciting news for all the Apple fans out there. However, it's almost impossible to validate the authenticity of any such leaked material until Apple officially announces the new OS.
Hopefully! the product announcement by Apple on Jan. 27th will bridge the gaps between the rumors and the reality.