Chess is a well-defined form of computation. You may not be able to work out the answers, but in theory there must be a solution. What IBM programmers have done is press the quest for the solution beyond the point where human thought processes can keep up with. It is using its immense number-crunching power to explore millions of moves per second and applying a set of rules provided by its human masters to pick the strongest. Deep Blue does not owe its intelligence to itself, but to a team of human programmers.
Computers are dumb.
When anything goes wrong with today's computers, they either stop or spew out nonsense. The human brain is far more resourceful, flexible and adaptable. No computer can translate a foreign language or speak English as well as a child. As a Christian, it is that humans are created in God's image. We both represent and resemble God.