Comparing Wolfram Alpha and Watson

A conversation recently led to discussion of the differences between IBM Watson and Wolfram Alpha. So what are the differences?   Our own experiences with 'expert systems', made us think about exactly this.    Every corporate systems deals with varied, large, rapidly changing databases.  Now we would like to get more out of them by leveraging them against specific paint points.  A view from Wolfram.  A now dated, but fascinating piece.