Bill, Chinese (and S.E.Asia derivatives) may be one of the toughest challenges for language recognition. Minimal variations in phonemes and ligatures lead to totally different meanings. On the opposite side Japanese, Russian or English (or even German) are very easy with clearly separated phonemes and unambiguous meanings. I dont see any of those languages about to disappear anytime soon. Portuguese for instance is spoken in a lot of countries... And Internet is more multi-linguistic than you may think
Back on topic, killer apps are games ! They require AI, the most CPU hungry process by far, which always get tuned (and tuned *down*) so it doesnt hog all the resources. There are some AI engines like connectivist and heuristic engines (neural networks, genetic algorithms) that are the future of AI, but require simply too much power to be used in real time yet. Of course AI can be used in speech recognition as well :P