Powerline fonts in vim & OS X 10.9 Mavericks
I have no idea why but the mappings in Parser.vim don't exist in the glyph table anymore for 10.9 (maybe the Unicode 6.3 support?). In the powerline docs it specifies that the glyph table starts at 0xE0A0 however in Parser.vim they're using 0x2B60 instead. On 10.8 it works because, in the case of 0x2B60 and 0xE0A0, the branch glyph simple exists in both locations.

You can try it by typing into a 10.8 terminal:

echo -n '\uE0A0'
echo -n '\u2B60'


Anyways, because 0x2B60 and the others do not exist anymore you just have to update autoload/Pl/Parser.vim to look something like this:

        \ 'fancy': {
            \   'dividers': [ [0xe0b0], [0xe0b1], [0xe0b2], [0xe0b3] ]
            \ , 'symbols' : {
                    \   'BRANCH': [0xe0a0]
                    \ , 'RO'    : [0xe0a4]
                    \ , 'FT'    : [0xe0a2, 0xe0a3]
                    \ , 'LINE'  : [0xe0a1]


Also, you'll probably have to run :PowerlineClearCache for it to take effect.