Just wanted to post that I also managed to get a build working on my MacBook Pro (2011) OSX 10.7 Lion, Using Xcode 4.5.2 and the steps posted by OmniStudent but substituting irrlicht 1.7.3 instead of 1.8. I also used target SDK 10.7, instead of 10.6, because 4.5.2 doesn't seem to include the 10.6 SD...