What are those 7 languages, anyway? The guy has a strong point he can make without exaggerating. If you want to capture > 90% of the mobile market, I think you only need Objective C and Java.

If you want the rest of the smart phone market, you'll need a C++/QT app, another Java app, and a .Net app. Conveniently, you can #include lua.h in all of these (except maybe BlackBerry) and end up only writing the UI code in the native language.

Or C#, thanks to the MONO guys...

I can think of 6 frameworks: iOS, Android, WP7, Blackberry, Palm OS, Meego.

It pains me to say, but MeeGo is a dead OS, at least on phones. Nokia has already said they'll ditch it even if N9 sells well.

Palm OS is obsolete too, they now use a version of webOS.

Ah yes. Write once, mediocre everywhere. Let's strive for that!

Javascript working on multiple platforms (browsers) isn't quite a new concept is it?

Sure IE6/7 had poor JS performance but IE7 is nearing death and performance of on mobile browsers is increasing rapidly (as well as CPU performance).

The performance isn't an issue, but Google Docs still isn't anywhere near the quality of Keynote or Word. iCloud will remove the advantage of instant synchronization, so there aren't many upsides (as a user) to avoiding the native app that adheres to your platform's interface guidelines.

Web apps were a natural bridge into the "cloud" world but now that we've all gotten good at decoupling our UIs from our backend and building all our web apps like a service native apps can just as easily be natural clients of the cloud.

Ultimately, whoever writes the checks gets to decide what to strive for. If you can afford to hire a developer for each platform, great. Otherwise HTML5 is a compelling alternative.