The US DOT’s Air Travel Consumer Report (300K PDF) summarizes quality of services issues for national frequent flyers. The Dane County Regional Airport reported the following for July, 2004:

• on time arrivals: 66.5%
• on time departures 79.6%

In a related note, former American Airlines CEO Bob Crandall discussed the industry’s woes and announced his new air taxi service (Pogo) during a speech yesterday at the Wings Club.
I believe “Pogo” type services will be the rule, over time, particularily for short routes.