Blog design best practice: Scrollbars not sidebars
briancray.com
briancray.com
So my caveat is that if you lose the side bar, don't allow your text to expand willy nilly!
Also there is the issue of too broad text chunks known both in typography and usability for making reading more difficult.
Apart from that I tend to agree with you.
http://blog.fawny.org/2005/09/21/measures/
In essence, most studies indicate longer line length leads to faster reading. But also, people on average seem to prefer having a moderate line length over a longer one.
In my view the latter measure is more important. I'd rather have a layout which is more pleasing than one which is faster to read.
(Of course ideally you have a variable-width layout so the reader can choose himself)