Interesting. It's a bit like Market Samurai with app store search results thrown in. I would love to see it pull in sales and grossing rank figures but they're a little harder to capture.
That was my conclusion as well. I'm working on a Market Samurai competitor, currently in pre-launch at: http://KeywordSear.ch
I'm wondering how they got this data, I would love to be able to offer App store specific research. I agree, sales and gross rank would really be slick.