Chances are that since ABC knows the show is such a hit, they decided to go ahead & start filming so they could have the next batch of episodes up by around Halloween or early November, along the same time-frame as the first season.
My only problem with this schedule is that if it turns out to be true, then season 2 won’t be a straight-through run. We’ll have to deal with random hiatus breaks just like this season. I’d be willing to wait for a January 2013 return to air date if it meant getting say a 22-24 episode season with no hiatuses & a straight through run from beginning to end.
Maybe that’s wishful thinking, only time will tell in regards to all this.