[kh99]

I think probably the "Array" comes from the "$post" that's just before <img...

ETA: I'm guessing you want something like this:

<if condition="$post['field11'] == 'alliance'">
   <img src="http://www.wowguideonline.com/forum/images/andromeda/misc/alliance-icon.gif">
<else />
   <if condition="$post['field11'] == 'horde'">
      <img src="http://www.wowguideonline.com/forum/images/andromeda/misc/horde-icon.gif">
   <else />
      $post[field11]
   </if>
</if>