Have you got Xcode installed?
I'm compiling with Xcode 3.2.6 on 10.6 without problems.
We haven't got a Mac Makefile for straight gcc compilation, but there's the Linux Makefile which could provide a good starting point if you wanted to try it.
Otherwise, have a look at the Juce forums. The build files for different platforms are generated using the Juce Introjucer - it helps us manage cross-platform compatibility.