Well, I've got TrinityCore running on my Mac either 10.6.8 or 10.7.3(which I've been using now).
First, Xcode matters. Xcode 3.x is best for 10.6 and Xcode 4.1 is best for 10.7, nothing else will work
Second, I installed git, readline, cmake through MacPorts. MacPorts would do all the things for you. (PS: If your Xcode if 4.1 and above, git will be installed by default, so just do with the other two)
Third, I compiled ACE directly from source, step by step as the wiki said.
Fourth, follow the wiki and finish the rest.
Create the file ACE_wrappers/include/makeinclude/platform_macros.GNU with this text:
note: what follows is not bash commands, you should create a file with name mentioned above, and the content should be:
debug = 1
shared_libs = 0
static_libs = 1
include ${ACE_ROOT}/include/makeinclude/platform_macosx_snowleopard.GNU
INSTALL_PREFIX = /opt/local