Here are ratios (percentages) for the week before, week ending 1/22/12 and matching week 1/23/11.
Year: new release / recent release / older release
2012: 33.0% / 30.2% / 36.8%
2011: 35.1% / 24.7% / 40.2%
difference between 2012 and 2011: -2.1% / 5.5% / -3.4%
As you can see, the new release strength was much lower than the most recent week, which makes sense since the box office strength was much higher (for the most recent week).
The differences here, between 2012 and 2011, are not so great in any of the three categories. The only notable differences are the recent releases being relatively stronger for 2012, and the older releases (carry over) being stronger for 2011.