Really, I fail to see a reason for using Objective-C or Java for writing mobile apps other than if it was some complex 3D game. But there are many reasons not to (code reuse between platforms!, plus IMO, as bad as people say JS is, I think it's a far more pleasant [esp. using CoffeeScript] language to program in then either Obj-C or Java).
So maybe the web browser is dead, because it's a "mobile app" accessed from some proprietary store vs a URL, but that's like saying the web browser is dead because someone pinned a web site to their desktop and uses that to access it instead of a URL. I just don't see why the distinction is needed.