In the
threadbit template, there is this:
HTML Code:
<if condition="$show['gotonewpost']"><a href="showthread.php?$session[sessionurl]goto=newpost&t=$thread[threadid]" id="thread_gotonew_$thread[realthreadid]"><img class="inlineimg" src="$stylevar[imgdir_button]/firstnew.gif" alt="$vbphrase[go_to_first_new_post]" border="0" /></a></if>
So, to determine if there is a new post, I suppose
$show['gotonewpost'] is what you are looking for.\
EDIT: My bad, I assumed this is what you were looking for--after re-reading your post, I don't think it is.