I'm assuming the rebanking of flights is bogging down operations at heavy hubs such as ORD, DFW and MIA. Even if you land early you often arrive late waiting for a gate. Waiting off the tarmac for 30 minutes+ seems to become much more common. A couple of months ago we sat for over 90 minutes as there was a broken a/c at our gate and the claim was that ORD didn't have any other gates to send our 763 to.