Bug 886670 has now been fixed, so you could use find_package(CGAL ...) instead of accessing internal variables like CGAL_CXX_FLAGS_INIT. find_package() will no longer inject internal flags that were used to build CGAL itself.
For a simple example run cgal_create_cmake_script on a trivial foo.cpp file containing a main() function. If you decide not to use find_package(), you can run make on the generated Makefile to see the default flags. Joachim