Nova Spivack, CEO of Radar Networks, which developed Twine says Wolfram Alpha may be as "important for the Web (and the world) as Google, but for a different purpose." He says "Wolfram Alpha is like plugging into a vast electronic brain. It provides extremely impressive and thorough answers to a wide range of questions asked in many different ways, and it computes answers, it doesn't merely look them up in a big database." "In this respect it is vastly smarter than (and different from) Google.
Here's a link to an article that compares the IBM Watson approach to the Wolfram Alpha approach: