Naturally, styling is subjective, but the report indicates GM plans to bring the Malibu's styling more inline with its larger Impala sedan, making changes mostly to the front fascia. As far as rear-seat room goes, it's worth noting that the 2013 Malibu actually has less legroom than the old 2012 model; 36.9 inches versus 37.6. Shoulder and hip room, though, increased by two and three inches, respectively, with the redesign.
In any case, without major structural changes, there's no way the Malibu will reach the rear legroom levels set by such large so-called midsize sedans like the Honda Accord (38.5 inches) or Volkswagen Passat (39.1) due to the fact that it's sized to be a global car and not one specifically for the US market. And, considering the impending existence of the 2014 Impala, we don't expect any major structural changes to affect the Malibu's interior offerings.
It's somewhat unusual for an automaker to make such significant changes to a car after only one year of production. But with all of the hype surrounding the emergency refresh of the 2013 Honda Civic, this sort of thing could become more common moving forward.