Vimscript for a live word count. Mixed match code from stackoverflow and added check for empty file: http://stackoverflow.com/questions/114431/fast-word-count-function-in-vim

vim-life-word-count

function! WC()
    if  getline(1) != '' 
        if &modified || !exists("b:wordcount") 
                let l:old_status = v:statusmsg  
                let position = getpos(".") 
                execute "silent normal g\<c-g>"
                let b:wordcount = str2nr(split(v:statusmsg)[11])
                let v:statusmsg = l:old_status 
                call setpos('.', position) 
                return b:wordcount
        else
                return b:wordcount
        endif
    endif
endfunction