Very nice! Here is a slightly changed version adapted to my own coding style (using '};' instead of '}' and pod documentation before each sub):

function GetPerlFold()
  if getline(v:lnum) =~ '^\s*sub\s'
    return ">1"
  elseif getline(v:lnum) =~ '\};*\s*$'
    let my_perlnum = v:lnum
    let my_perlmax = line("$")
    while (1)
      let my_perlnum = my_perlnum + 1
      if my_perlnum > my_perlmax
        return "<1"
      endif
      let my_perldata = getline(my_perlnum)
      if my_perldata =~ '^\s*\(\#.*\)\?$'
        " do nothing
      elseif my_perldata =~ '^\s*sub\s'
        return "<1"
      elseif my_perldata =~ '^\s*=head.\s*'
        return "<1"
      else
        return "="
      endif
    endwhile
  else
    return "="
  endif
endfunction
setlocal foldexpr=GetPerlFold()
setlocal foldmethod=expr
[download]

This will let the pod lines between subs out of the folds. The original version will fold the pod lines with the previous sub.