I found it interesting that James Fallows and David Brooks wrote columns more or less simultaneously about Barack Obama's calm demeanor and what it might mean. Both pieces are worth a read.
Fallows: OK, I lied, one more thing about debates
Brooks: Thinking About Obama
If you read the Brooks column be sure to check out the reader comments; here's a link to 8 of the 636 comments which were judged interesting by the editors. You can also filter the comments down to ones that readers recommend.