iOS 9.3 is coming in the Spring and will introduce Night Shift as well as a number of other new features.
iPhone SDK Details: Apple as Gatekeeper, No Accessories?
iTunes Store as hub - as expected, Apple will require future iPhone and iPod Touch applications to be distributed through Apple's iTunes Store.
Apple as Application Gatekeeper - iLounge believes that Apple will act as a gatekeeper for the applications themselves and will formally approve or deny all software releases:
While one source saw this as a positive for major developers, suggesting that Apple will be choked by application submissions and forced to give priority to releases from larger companies, another source disagreed, stating that Apples current approval processes for third-party products have resulted in lengthy, needless delays.No Accessory Support - no ability to support dock-based accessories (such as a GPS module), though the iPhone's own phone, Wi-Fi, and camera will reportedly be accessible.
iLounge corroborates earlier rumors that the final SDK would not be ready for release at Apple's March 6th event. Instead, they echo that a beta will be available then, with the final release to await WWDC in June. Meanwhile, they do expect Apple to announce Microsoft Exchange and Lotus Notes support at the March event.