Rei Vilo has developed embedXcode, a Xcode 4 template for embedded computing boards, that supports Arduino, chipKIT, MSP430 LaunchPad, LeafLabs Maple and Wiring boards/platforms.
“It relies on a set of modular makefiles, so adding support for a new board/platform is easy. The makefiles can also be used with any standard IDE, for example NetBeans. I hope embedXcode could help developers with a more advanced IDE on OS X.”
You can learn more at the embedXcode webpage.
Via the contact form.