You're actually using a C++11 technique there: initialiser lists. Unfortunately although the compiler will happily build it, the 10.8 runtime doesn't contain the C++11 std library functions that it relies on, so you can't use it.
But you can use C++11 and deploy to 10.8, see Timur's post on how deployment setting interferes with standard compiler setting: http://www.juce.com/comment/318838#comment-318838
Just set it explicit to the language you want and the library setting.
I'm going to cross-thread-quote timur here (hopefully nothing locks):
If you set it to 10.8, then the default is not C++11 anymore, and you'd have to set C++11 and libc++ manually (after which everything compiles happily).
That was it! It's compiling now, and all the initalization errors have fallen away.