That's true and probably the reason why interfaces improved so much. Whitespaces are a design element and what you call junk is somebody business need.
The fact that the blank canvas got bigger on the web allowed to much better interface patterns, or maybe it was just a question of maturity.
But I guess the most interesting discussion is not the visual part but the utilization scenarios of the Ipad. I'm not sold on it as a mobile device, but how many people use a laptop as a mobile device? Mobile phones are the first truly mobile devices.
I'm just starting to notice Iphone owners on the middle of a crowd trying to text somebody, you have to hold it closer to the horizontal plane to have better accuracy making it less natural.
I'm not sold on the Ipad as a mobile device, in the mobile phones sense, but I also don't think its success depends on it.
Putting the junk in the extra space means it's not clogging up the content area (except on truly awful websites). It means they can include all the extra crap no one really wants, while still keeping the site usable.