WolframAlpha the factual search engine by Wolfram is going to be released on may 2009. It is a computational engine for the web that is going to be launched by Wolfram.It is going to be a very big project as it will answer to your factual questions.It may become quite popular but till the launch of it just wait and watch what is it going to be ,otherwise its fate maybe same as that of Cuil.
According to Wolfram it is a engine which can answer your factual questions and you don’t need to go the google and type the queries for the question like ” First Gold Medal at Sydney olympics” ,”Where is Taj mahal located” and so on.
It is not a search engine which will give you various results or not a giant database like Wikipedia.It is a engine which computes the answers. Means it first understands the question and then tries to answer the question.
But do you think any machine can compute the answer like ” How many centuries Sachin has scored”. It will oviously use databases and then search the exact query. Just my logic. You can read the complete review here in techcrunch.