So Xcode 4.3 was released last week and now lives in /Applications rather than having its own /Developer folder. This has needed some major changes to how it is installed and used so Peter Hosey wrote a great run down of the main changes and what tools have been moved to where.
Chris Parker with a solid gold piece on separation of responsibilities within your code. Taking Chris's advice on this subject is something we should all strive to do, and not only because it will make his job at WWDC easier.
Don McAllister writes about the various ways to capture screencasts of your iOS apps, useful for creating marketing or training resources. As he says though, a bigger problem than capturing the output is effectively showing interaction which is a problem not only when recording video output but also when using your app via a projector.
Apple have published a set of beginner guides to help people new to iOS development. They cover everything from a tutorial on how to build your first app right through to articles on design patterns, interface design and uploading to the app store.
This is something I used to take advantage of when I was writing Mac apps but never took the time to research it on iOS. Matt Gemmell gives a good overview of the process and has some useful links to additional code and tools which will make using PDF images easier to deal with.
Nik Burns on the settings URL schema which allowed deep linking into the settings app but which is unfortunately gone in iOS 5.1. Nik also has a radar number to dupe if you want to voice your opinion to Apple on this as well.