the big white bars in desktop? I'm okay with it. when reading, it is easier when the content is compacted. if the text was full length of a browser, supposedly it is harder to read or people lose interest. Now, youtube is video, so I'm not sure whats up with their white bars but I digress.
Even Google Reader had a maximum width of its content with any white space being on the right side of the content. I MUCH prefer this UI.