A few days ago I wrote about Google putting their weight behind HTML 5 and now it looks like Palm is pushing it too. The "mojo" developer's kit is based on HTML 5 and uses Javascript as the primary language. I still have some serious reservations about building serious apps in javascript. It just feels fagile. Bailing wire and chewing gum is not the feeling I want when building apps. The unholy alliance of javascript and HTML has made web apps a lot more interesting but it's still a very breakable platform.
Palm has taken an interesting approach though. They are providing a library of application components that are scripted by javascript. Palm has most likely built those core modules in c++, java or something more robust. Javascript is used, as it's name implies, as a scripting language.
I'll be keeping an eye out to see how successful this combination becomes.