So which language is the "best" for mobile development? As with so many other topics in the software development world, the best answer is "it depends." If you want to do native development on iOS, your hand is forced. If you want to build an app with a browser front-end, have rich media as part of the experience, and would like to have your app relatively future-proofed, then there's only one real choice. For everything else, you'll have to look at the experience in your staff, the needs of your users, and the budget for the project.
People tend to be invested in languages and systems. Which would you choose? Where have you made your mobile development investment? I'd love to hear what you have to say.