Java apps still require an install and you cannot seamlessly navigate between them. Now if Someone would create a java plug in, and if this plug in could be run in all browsers, then you'd have something. An alternative solution is to create a "navigator" shell app that works like a browser, except for java apps. In either case it would be nice to create a display language like xaml designed for visual styling, multimedia, and databinding. This wouldn't be strictly necessary as java has the swing library already (I guess- all my work with java has been limits to jsp, so my visual styling was done in HTML), but it would greatly aid developers in creating the rich content users are expecting these days.

The problem with a new, browser style "navigator" app, is that you have to convince users to install it and developers to write for it. Additionally users have to decide when they start their session whether they are going to be consuming or interacting. The issue with a plug in is getting the ipads of the world to support it. You might have more success with Java because it is open.

Either way, clearly the experience users want is to open his or her browser, hit a link, log in, and do their business. When they are done with that business, the want to go to a new link (maybe found via search) and do new business elsewhere. They may even want to browse some documents in between and likely want to do it all in within the same context. The java of today does not support this experience and the only way to deliver it is through a plug in or manhandling HTML.