iOS 9.3 is coming in the Spring and will introduce Night Shift as well as a number of other new features.
Apple Releases Firmware Updates for 'Late 2008' Portables
EFI Firmware Updates: The Extensible Firmware Interface (EFI) specifies the interface between a computer's firmware and the operating system. These updates address several issues related to system stability. Further information and installation instructions can be found on Apple's support page.
SMC Firmware Updates: The System Management Controller (SMC) controls various power-related functions. According to Apple, these updates address the "sensing and accuracy of the MagSafe Power Adapter indicator light, and the battery charge indicator lights." General information and installation instructions for SMC updates can be found on Apple's support page.
MacBook EFI Firmware Update 1.3 (1.8 MB)
MacBook SMC Firmware Update 1.2 (556 KB)
MacBook Pro EFI Firmware Update 1.6 (1.9 MB)
MacBook Pro 15-inch SMC Firmware Update 1.2 (559 KB)
MacBook Air EFI Firmware Update 1.1 (2.4 MB)
MacBook Air SMC Firmware Update 1.1 (556 KB)