Mac OS X: Mountain Lion has been released, which comes complete with lots of new features and security improvements. One minor annoyance, particularly relevant to Vim users, is the handling of emoji glyphs. Emoji are pictographs often available on mobile devices that have started to bleed into Apple's operating systems.
Where the problems start is Apple's glyph substitution algorithm. Some fonts are incorrectly displaying glyphs from Apple Color Emoji.ttf, and this has been found to occur in text-based command-line applications, and affects both iTerm2 and the built-in Terminal app. Rather than getting the fancy characters Powerline uses, or modern zsh Unicode shell prompts, people are seeing weird and wonderful emoji glyphs instead.
It modifies PTYTextView so that it creates an NSFont that specifies a cascade list that contains 'Apple Symbols', which takes precedence over 'Apple Color Emoji'.
I'm using one of the Powerline patched fonts, and I found this means I don't see the problems reported above... so far.