iOS 9.3 is coming in the Spring and will introduce Night Shift as well as a number of other new features.
iOS 4 Due for Release Today
iOS 4 packaging for iPhone 3GS from Br8nd4on.com
Apple is due to release iOS 4 sometime today. The latest version of the iPhone and iPod touch operating system will be available as a free download. It appears Apple has already started shipping the new iPhone 3GS 8GB with iOS 4 pre-installed (see photo above).
We aren't sure when Apple will be posting the download. Last year's 3.0 release didn't take place until after 1PM Eastern/10AM Pacific.