What's new and what's missing in iPhone OS 2.2.1 SDK

About two months after releasing its iPhone OS 2.2. update, Apple quietly issued the iPhone OS 2.2.1 SDK. As the extra decimal place suggests, 2.2.1 is by no means a radical overhaul, but a relatively simple bug update sans significant API changes, designed for developers building for devices upgraded to the new iPhone OS 2.2.1 firmware revamp. Labeled Build 9M2621, the complete package contains the iPhone SDK and Xcode 3.1.2 Developer Tools for iPhone OS 2.2.1--according to Apple, the new SDK adds support for targeting non-Mac OS X platforms; GCC 4.2 & LLVM GCC 4.2 optional compilers for use with Mac OS X 10.5 SDK; updated assistants to create new projects, targets and source files; integrated SCM support interoperable with Subversion 1.5; and a simplified toolbar. Download the iPhone OS 2.2.1 SDK here. http://developer.apple.com/

Still MIA from the iPhone OS: The unified push notification service Apple promised all the way back in June 2008 at its Worldwide Developer Conference. The push service--which alerts iPhone users running one application when fresh data is available for another application not in use--became necessary when Apple declined to include background applications in the iPhone SDK; many developers cited their concerns about such a limitation, arguing it could restrict the usefulness of applications like instant messaging. Speaking at WWDC, Apple senior vice president of iPhone software Scott Forstall told developers that work on the push service would be completed by September--the computing giant has not offered an explanation for the continued delay.

For more on the iPhone SDK update:
- read this Softpedia article