i think most relevent part of 'Art of War' today is his politic thoughts and philosophy. There are also parts in the book where he actually talked about how to fight a battle like how to deploy archers or what formation spearmen should line up, i think that would be interesting reading only for historians. Its really a good book to read over some time and apply it to your personal life.
As for its military value in today's warfare, i think its more useful to politicians than to generals. Warfare has changed since his time, only thing that hasnt changed is politics.
Of course its a good reading for anyone who likes to be more sophisticated, but good luck on the archaic chinese.