I'm just doing some preliminary design.  The game will use a silverlight front-end that ties to a WCF web service which will store the game history in a XML file. I know that I'm going to store the game as a list of moves borrowing from the chess layout and notation.

 The XML format will be something like this:

<SilverlightChecker>
<Game ID="1">
      <Moves>
              <Move>3a-4b<Move>
      </Moves>
</Game>
</SilverlightChecker>