I didn't test it personally as I don't have ML yet, but it should work. There were two bugs in the RC that are now fixed, however they are not related to OS X directly but rather Xcode. And they don't influence the installation process.
Issue #233 can be fixed "by hand" very easily.
Issue #212 can be workaround by using frameworks and not dylibs.
(However, other bugs were also fixed, like
this one. But this doesn't break the installer at all.)
@DavidJohns: if you compile SFML yourself you can automatically install the new version of the templates. Search for "SFML_INSTALL_XCODE4_TEMPLATES" in the tutorial.