Hi good ideas.

I had a look at the way Air Blast did it's missions and it was a simple command based system.

I think I'll go down the xml route (the rest of my app has) with a combination of scripting where needed.

Code:
<level name="Level1">
   <teams>
       <team name="Player"/>
       <team name="Enemy"/>
   <teams>
   <objects>
       <object name="Item1" team="Player">
          <controller></controller>  <!-- define who controls the object here -->
          <position x="" y="" z=""/>
       </object>
   </objects>
   <events>
      <event name="">
         <conditions>
            <condition></condition>
          </conditions>
          <actions>
            <action></action>
          </actions>
      </event>
   </events>
</level>
That looks about right. I know people are sometime against xml for games, but I think it's a nice easy format to edit and update.

Dean