Since the MacBook Air was refreshed earlier this year we had assumed that once the 2013 MacBook Air was released, it would come with the same Haswell chip. We knew there would be a slightly faster version, but we never thought Apple would go for a different architecture.
The new MacBook Pro now comes with a Crystalwell processor, and we were told during the event that this offers increased battery life and performance. However, this is only for the 15-inch version, as the 13-inch Pro has the same Haswell chip as the Air.
The all-new MacBook Pro with its new Crystalwell chip is a quad-core processor and includes Iris Pro Graphics. This offers superb graphics performance, but is able to achieve this with less power.
However, there is still a compromise, so if you want to get even more from your new Pro, then you can go for the Nvidia GeForce GT 750M discrete graphics option instead.
You also get 2GB of memory on the graphics, which means all in all you get faster processing power and graphics, and longer battery life as well, up to 8 hours in fact. All this is explained in detail on the Apple website, and a lot more because there is so much more to the 2013 MacBook Pro refresh.
Also See: iOS 9 release time for GM download