You can get reasonable version control integration from zsh without any kind of wild oh-my-zsh config. Most distributed versions of zsh are compiled with vcs_info enabled.

    autoload -Uz vcs_info
    zstyle ':vcs_info:*' enable git hg
    zstyle ':vcs_info:*' check-for-changes true
    zstyle ':vcs_info:git*' formats "%{$fg[cyan]%}(%{$fg[green]%}%s %{$fg[blue]%}%r%{$fg[cyan]%}:%{$fg[green]%}%b%{$fg[yellow]%}%m%u%c%{$fg[cyan]%})%{$reset_color%} "

    setopt prompt_subst
    export PROMPT="%{$fg_bold[red]%}%n%{$reset_color$fg[white]%}@%{$fg_bold[green]%}%m%{$reset_color$fg[white]%}:%{$fg[cyan]%}%1~ \${vcs_info_msg_0_}%{$fg_bold[white]%}%(#.#.\$) %{$reset_color%}"