brew install -v macvim --no-icons
mv /usr/local/Cellar/macvim/snapshot-55/MacVim.app /Applications/

The --no-icons switch is a fix for:

PhaseScriptExecution "Make Document Icons" /tmp/...
(1 failure)

For use with Janus:

" Position and maximize window
:winpos 0 0 " Center window
vsplit " Split window vertically
wincmd l  " Move to right window
split     " Split window horizontally

" Remove stuff
set guioptions-=L
"set guioptions-=r " Disable window resize
set guioptions-=T
set fuopt=maxvert,maxhorz " Maximize width and height
endif

.vimrc.before:

"call janus#disable_plugin('nerdcommenter')
let mapleader = ","

highlight OverLength ctermbg=red ctermfg=white guibg=#592929
match OverLength /\%81v.\+/

map <C-h> 5<C-w>>
map <C-j> 5<C-w><
map <C-k> 3<C-w>+
map <C-l> 3<C-w>-
map <leader><leader> :ZoomWin<cr>

set undofile
set undodir=~/.vimundo/

set wildignore+=*/tmp/*,*.so,*.swp,*.zip,*/log/*,*/vendor/bundle/*

let g:ctrlp_working_path_mode = 0
let g:ctrlp_max_height = 30

" No wrapping
set nowrap
set textwidth=0 wrapmargin=0

" Strip trailing whitespace
function! <SID>StripTrailingWhitespaces()
    if &ft =~ '\|ruby\|javascript\|perl'
        return
    endif
    " Preparation: save last search, and cursor position.
    let _s=@/
    let l = line(".")
    let c = col(".")
    " Do the business:
    %s/\s\+$//e
    " Clean up: restore previous search history, and cursor position
    let @/=_s
    call cursor(l, c)
endfunction
autocmd BufWritePre * :call <SID>StripTrailingWhitespaces()

Optional .gvimrc.after:

colorscheme jellybeans
" colorscheme molokai
"colorscheme vibrantink
set guifont=Monaco:h13

" Position and maximize window
:winpos 0 0 " Center window
vsplit " Split window vertically
wincmd l  " Move to right window
split     " Split window horizontally
set fuopt=maxvert,maxhorz  " Maximize

" Remove stuff
set guioptions-=L
"set guioptions-=r " Disable window resize
set guioptions-=T

Optional .vimrc.after:

colorscheme vibrantink

I'm switching from Janus to Vundle, and I found this command useful in the migration process:

/usr/local/Cellar/macvim/7.3-66/MacVim.app/Contents/MacOS/Vim -v --startuptime /dev/stdout +qall