<!--original markup-->
<strong>I AM STRONG</strong>
<strong>I AM STRONG</strong>
<strong>I AM STRONG</strong>
<strong>I AM STRONG</strong>
<strong>I AM STRONG</strong>

<!-- new markup -->
<div>
    <strong>I AM STRONG</strong>
    <strong>I AM STRONG</strong>
</div>
<div>
    <strong>I AM STRONG</strong>
    <strong>I AM STRONG</strong>
</div><div>
    <strong>I AM STRONG</strong>
</div>

var elems = $("strong");
for (var i=0; i<elems.length; i+=2)
{
  elems.slice(i,i+2)   // split off a pair
    .wrapAll("<div>"); // wrap it
}

$('strong:odd').each(function(){
  var divElement = $('<div></div>').append($(this).prev(), $(this));
  // Now add the divElement to a new container?
});