It could also be possible that it could have the i5-750 or 750S, which are quad-core chips.
Although, knowing Apple, it'll only be the i5-520 or 540 in the 13.3 and low-end 15.
So would it be worth it to go from the current model 2.53 to the i5? I just bought one for my kid on the 31st for college. It is going to have to last for four years.