親と同じ高さの div で垂直方向に配置されたテキストをラップし、それを display:table-cell します (親をテーブルとして表示した後):
HTML
<div class="row">
<div class="small-6 column">Lorem ipsum dolor sit amet, consectetur adipiscing elit. Etiam et iaculis justo. Mauris bibendum convallis est, vel blandit quam tempor aliquet. Cras euismod nibh et nisl congue, eget tincidunt mauris consectetur. Donec eu risus lectus. Integer at ipsum sed turpis fringilla adipiscing vitae vel enim.</div>
<div class="small-6 column"><div class="v_align">Some text</div></div>
<div class="clear"></div>
</div>
<div style="width:200px; height:100px; background:#0f0; color:#fff;">dfbvd bdfhgf hfg hghf gfdh hfgghfd hgf</div>
CSS
.row{
width:300px;
height:auto;
}
.clear{clear:both;}
.column:first-child{
color:#f00;
background:#ccc;
}
.column:nth-child(2){
background:#999;
color:#00f;
display:table;
}
.column{
width:150px;
float:left;
}
.v_align{
display:table-cell;
vertical-align:middle;
}
JS
$(document).ready(function(){
var rowHeight = $(".row").height();
console.log(rowHeight);
$(".column").height(rowHeight);
$(".v_align").height(rowHeight);
});
結果を確認してください: http://jsfiddle.net/gespinha/h6aPf/6/