The market you're after is people who want to learn a new language. The want they have, is to learn a new language. The question then, is "will this be something people learning a new language will want?"

I don't think this is the best way to learn a new language. Learning requires you to push yourself slightly beyond your comfort level/what you know. If you push too far beyond what you already know, learning will be ineffective. The success of a learning system is dependent on how well it is able to push you selectively. This seems like it'll be pushing people "too far".

This does seem like a good technology though. I think it can be coupled with another language instruction system. Mostly for people who've already done a lot of learning, but are looking to solidify their knowledge.