There's a class of application that will never make sense to be stand-alone, and for those apps, the cloud is probably the best paradigm. But the current state of HTM5/Javascript calls for a cloud with a ton of application logic running in the browser. I'd much rather see a single app running in the browser that isolates all the front-end specifics and makes it really easy to write fully server based apps that use the browser as a universal delivery system - and nothing else. Sure, you're not going to write video games that way. But I'm talking about apps that handle data input and output with a robust widget set that doesn't need to be programmed on the front end. A smart terminal that lets you generate, say, data to be displayed in a grid on the server and just send it to the terminal for display and manipulation.
I wrote something just like that a long time ago - though it doesn't run in a browser - so the smart terminal requires Windows or WINE to run. That no longer cuts it, but as a proof of concept it works really well (and is still in use). The data grid, for example takes grid layout instructions and a file in a 'CSV with flags' format that is produced on the server for display (and editing) in the terminal. Besides making the app easy to implement and debug, that level of abstraction has some nice side benefits. 'Printed' reports come for free, because the data and the instructions for laying it out in a grid are generated separately from the display logic, and it was easy to implement a printing module that takes that same info on the server side and uses it to generate a PDF or XLS file for download and native display/printing. I guess it's essentially splitting the MVC model so that only the View part (the part that has to run on the client) runs on the client.
I can't be the only one that's done something like this - but I'm curious why I don't see anyone trying to adapt that model as a browser-based application platform. Just because Javascript lets you write application code that runs in the browser, that doesn't mean it's a good idea - or that the end result is easy to write, debug and support. The browser's a really smart terminal, but maybe it would make sense to write a browser application that turns it into a somewhat dumber terminal - that only does terminal-like stuff.