Not everything is classification and there are problems better solved with other methods. For example I also haven't seeing anyone playing chess or go with DBN's. Also Compression, general programming...
Classification is a huge part of chess programs. You need to quickly evaluate a millions of boards to decide which side has the advantage. However, do to the well understood rules we can write efficient classifiers by hand.
Go is a much harder problem in large part because it's really hard to accurately classify which board is better off.
Teaching Deep Convolutional Neural Networks to Play Go: "Our convolutional neural networks can consistently defeat the well known Go program GNU Go... It is also able to win some games against state of the art Go playing program Fuego while using a fraction of the play time."http://arxiv.org/abs/1412.3409
