So, have you ever wondered where the Google GeoEye 1 satellite is? I have... and now, Wolfram Alpha can tell me th real time position! Click here to see. I think this Wolfram Alfa thing is pretty cool if you happen to want to know a bunch of statistical data about a data set, or you want to quickly graph a fractal, or you just want something about the stuff listed on this page. I think it's really neat.
Wolfram Alpha isn't a search engine. It's a computational knowledge engine. I don't see it replacing Google for everything, however it is supplement to Google. The main reason is because it has a strict syntax... you can't just type in whatever is on your mind, but if you want to know the median wage of a Software Engineer... well, it can give you a quick answer, and it even gives you an option to save the results as a PDF.
So, if there is something you want to know, head on over to Wolfram Alpha and just try typing it in. You may just be surprised what you can find.