User blog comment:Sannse/Sneak Peek at the New Look - Themes/@comment-617149-20100915213422/@comment-400262-20100915220600

Afaik the width of the sidebar is so that a standard box and can be placed there. A lot of people were complaining about ads within the articles themselves, so in order to be able to put them in the sidebar it had to be widened. It's really a choice between the devil and the deep blue sea.