Here's a counter point, though. For readability, you should make your text blocks around 33em wide, which is about 66 characters. If you lose the side bar, you have to choose between really long lines, which suck, or multiple columns which is a chore at best, and impossible at worst since columns only really work in the format of a "page," since the reader would potentially have to scroll down then scroll back up for the next column.
So my caveat is that if you lose the side bar, don't allow your text to expand willy nilly!
Good point, except for not practicing what you preach (perhaps that will come later?). The social networking section above the comments takes up more than a third of the height of my screen.
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)
So my caveat is that if you lose the side bar, don't allow your text to expand willy nilly!