Commercial CNC machines and other motion control applications will _never_ run off of web-based software. Not to say it isn't possible under the right conditions, but those conditions can't be ensured. There will always exist applications that require low response times that the internet cannot dependably deliver.

High end CAD and CAM software also falls under this umbrella. There is simply too much computation/rendering occuring.

no,the OS you'll be working on will be designed so it will be harder to tell wether you're using a webapp or a native app.