@squawell: yes i know, it was planned so
if you want to change it so the first post alwas looks different, no matter of admin or normaluser
you have to post the block where $templatename is defined and do the changes there more specific.
@Ryangel:

You're half right, post doesn't have a usergroupid field, but a join query was executed with the user-table and so there is a $post[usergroupid] defined