Considering that 90 seconds of air time doesn't come cheaply, even for a company like Apple whose cash reserves dwarf those of Scrooge McDuck, Apple wisely broke the bigger commercial up into two 30 second spots. Not only does this allow Apple to grab open air time when it can, the tech titan can get the message across at a lower price.
Apple has also started up a "Your Verse" website that goes into more detail about the people in the ad and the unique ways they employ their iPads. You can view both spots by clicking on the videos below.
source: Apple (1), (2) via MacRumors