I have same feeling. Youos is wonderful but I always feel it waste too much screen space. On the other hand current browser is not very suitable for running multiple web apps also. Maybe we need a better container...
But really, what we are talking about is just a resurgence of thin clients. And why not? They make sense. No updating software, all your files are there for you whereever you go and today we have the bandwidth to handle it (we do vid downloads without batting an eyelid!).
Especially with Google's gears coming along, it will mean we can do everything offline. It's getting close to CMS your home dir and apps.
When I was in high school (15 years ago or so) I said the perfect computer app would be one where you didn't know it was there and just used it to do what ever you wanted, like in TNG. This is getting close!
2. Local storage
3. Local storage
We can put different page ('apps') in different tabs and windows, which is perfect for running multiple apps.
Current browsers are designed for maximum surfing productivity and not dedicated to provide a perfect web application container.