I think it's weird that they'll gloss over CPU details, opting for "2x as fast", but then when the camera talk comes around, they go on and on about optics, filters, image processing, etc. I'm not sure why they go into so much detail on the camera details.
In practice, modern phone SoCs are fast enough for most purposes. It's not like the 4S (or even the half-again-as-fast 4) are slow. A great improvement won't really make too much difference to most users. Smartphone cameras, on the other hand, are still somewhat lacking and an improvement will benefit most users substantially.
It's to counter the needless and destructive megapixel race in phones. Until they get their claws on something truly gamechanging like Pureview they need to train their customers to talk about camera quality, not megapixellage.
