The text width of the posts in the forums is rather big and makes it, at least for me, difficult to read. Sometimes I even need to scroll horizontally which really is a PITA.
To some extend this also goes for the news articles, but they're not as bad as the forum.
So my wish would be to use something like a 60-80 chars/line limit.
@Michael: as a funny aside, I found the following PDF which deals with the representation of online resources more deeply; with lots of reader's "benchmarks" in it, I thought it perfect to back up my wish.