There has been some discussion in our office as to what is semantic HTML and whether the following code is semantic HTML...any input would be appreciated. Thank you in advance for your advice.

Code:
<div id="contentWrapper">





<div id="calloutBox">
<div id="calloutSpacer"></div>
<div id="calloutImage"><img src="http://www.domainname.com/images/callout-icon.png" alt="Breaking News" title="Breaking News" /></div>
<div id="calloutContent">Dummy text goes here...A wonderful serenity has taken possession of my entire soul, like these sweet mornings of spring which I enjoy with my whole heart. I am alone, and feel the charm of existence in this spot, which was created for the bliss of souls like mine. I am so happy, my dear friend, so absorbed in the exquisite sense of mere tranquil existence, that I neglect my talents.</div>
</div>



     
<div id="navBoxes">

<div id="navBox1">
<div align="center" class="boxImage"><a href="../index.htm"><img src="images/features/description_icon.png"  alt="Alt Text Goes Here" title="Descriptive Text Goes Here" /></a></div>
Describe destination of link in 70 characters or less&mdash;including spaces.
<div align="center" class="boxLink"><a href="resources/index.htm">Anchor Text Goes Here</a></div>
</div>

<div id="navBox2">
<div align="center" class="boxImage"><a href="../index.htm"><img src="images/features/description_icon.png"  alt="Alt Text Goes Here" title="Descriptive Text Goes Here" /></a></div>
Describe destination of link in 70 characters or less&mdash;including spaces.
<div align="center" class="boxLink"><a href="resources/index.htm">Anchor Text Goes Here</a></div>
</div>

<div id="navBox3">
<div align="center" class="boxImage"><a href="../index.htm"><img src="images/features/description_icon.png"  alt="Alt Text Goes Here" title="Descriptive Text Goes Here" /></a></div>
Describe destination of link in 70 characters or less&mdash;including spaces.
<div align="center" class="boxLink"><a href="resources/index.htm">Anchor Text Goes Here</a></div>
</div>

<div id="navBox4">
<div align="center" class="boxImage"><a href="../index.htm"><img src="images/features/description_icon.png"  alt="Alt Text Goes Here" title="Descriptive Text Goes Here" /></a></div>
Describe destination of link in 70 characters or less&mdash;including spaces.
<div align="center" class="boxLink"><a href="resources/index.htm">Anchor Text Goes Here</a></div>
</div>

</div><!-- end navBoxes div -->
        


        
<div id="contentBox">

<p>Dummy text goes here...A wonderful serenity has taken possession of my entire soul, like these sweet mornings of spring which I enjoy with my whole heart. I am alone, and feel the charm of existence in this spot, which was created for the bliss of souls like mine. I am so happy, my dear friend, so absorbed in the exquisite sense of mere tranquil existence, that I neglect my talents. I should be incapable of drawing a single stroke at the present moment; and yet I feel that I never was a greater artist than now.</p>
        
<h3>News &amp; Publications</h3>

<ul class="singlespaced-nondecorated">

<li><a href="#">First News Item Description Link Goes Here</a></li>

<li><a href="documents/placeholder.pdf" target="_blank">Second News Item Description Link Goes Here</a><img src="http://domainname.com/images/icons/icon_pdf.gif" alt="PDF" width="16" height="16" /></li>

<li><a href="documents/placeholder.pdf" target="_blank">Third News Item Description Link Goes Here</a><img src="http://domainname.com/images/icons/icon_pdf.gif" alt="PDF" width="16" height="16" /></li>
        
<li class="topMargin25">Visit the <a href="#">News & Publications</a> page for additional archived items.</li>

</ul>

</div> <!--END contentBox div-->




</div><!-- end contentWrapper div -->