Sort of. The key difference is that B2G is aiming to allow web apps to do absolutely anything a native app can do, whereas on the iPhone it was just intended to augment the native experience. That's how I see it, at least.

More similar to the (initially announced) Palm Pre. It was supposed to be a device which runs Web Apps natively, and you write your applications in HTML + JS, using their "Mojo". Well, developers weren't having it, so they eventually allowed C / C++ as well. I'd predict the same with this device. Since it's running Linux kernel, I can pretty much guarantee that you will be able to run C / C++ apps on the device, and developers will choose that more often than not.

You didnt have to write them with Mojo, you could write them with any HTML/JS framework, or just roll you own. Mojo was just the one the Palm apps (Email, Web, Phone, ..) used.

And a vast majority of the apps for the platform used it for UI. C/C++ was generally only used for games ported from iOS to webOS, or when writing a custom plugin for some capability not provided by the service architecture.

C/C++ was allowed, but definitely not chosen "more often than not" on webOS. The UI for a vast majority of the apps was HTML/JS and using Mojo.