It was a slightly daft question in fairness. The question is not if 2 seconds is a lot within a class (it's obviously huge), only if since they're (on occasion) that close now, is it possible that the Caterhams and Marussias will be pushed back to less than GP2 performance. 2 seconds might be a lot, but it wouldn't be that hard to add 2 seconds to an F1 lap time by reducing wing size.
Smaller wings would not reduce lap time by that much. All you do is increase top speeds on a long straight and since that would REDUCE the speeds on high speed corners or just fall off the circuit, you would be back where you started. Balance is where lap times are improved overall, that and a better chassis/aero ballance. Balance being the operative point.
Also in 2013 the drivers could use drs only on the drs areas of the track during sessions but in 2012 the drivers could use drs everywhere on the track during practise and qualifying. So that slowed the cars down as well. Plus the floor tweaks and exhaust-diffuser rules changes at the end of 2011 season.