[Deff]

<table><tr>
<td class="ms-cellstyle ms-vb2">
 &lt;DIV&gt;&lt;IMG height=25px src=http://javascript.ru/forum/images/smilies/smile.gif&gt;&lt;/DIV&gt;</td>
</tr></table>
 <script>
  function myInnerTxt(str){
     var p = document.createElement('p');
     p.innerHTML = '<textarea>'+str+'</textarea>';
     return p.firstChild.value;
  }
  var el = document.querySelector(".ms-cellstyle.ms-vb2");
  el.innerHTML = myInnerTxt(el.innerHTML);

 </script>