This is a plain, ribbed beanie hat. It is called Exeter because of the way the crown decreases interact with the ribbing. It is reminiscent of the ceiling in the nave of Exeter Cathedral.
The 2x2 tubular cast-on is a great way to start this hat. Ysolda Teague has a great tutorial on long-tail tubular cast-on.
Dec. 2014: I have updated the pattern to replace all of the left/right decreases with explicit ssks, k2togs, p2togs, and ssps. Also, there is now a chart.