The lines are tremendous. I'd say that two hours is the minimum amount of time that you need. To check the luggage at delta you have to wait in a line with about two hundred other people. Then you must wait in another line with double that amount to go through the metal detector and have any carr on's checked out. After you accomplish this, you can freely take the shuttle to the gates where, you guessed it, you'll be asked for your ID again befroe boarding the airplane.
Don't get me wrong here, I appreciate the security. The lines do move so it isn't that bad, but you must get there early.
One small thing that I found interesting. We, and a lot of other people returning from Walt Disney World, had no problem getting on the airplane with a lot of trading pins. Not that anyone is going to be successful hijacking a plane with a trading pin, but I thought that you couldnt bring anything sharp through security?