So many Apple haters, its actually comical to read. "omg dey just mayd it thinr" and the likes.
First off, the chip is more powerful and has a more dynamic range of things it can do for applications. Its got a more powerful processor, nearly double what the current model has, as well as improved graphics - meaning that the people that take iOS gaming seriously (read: a lot of people) will get a better experience.
The touch screen is also integrated right into the glass, instead of having a seperate layer, which not only means that the system is thinner, but its also less prone to screen glares. We also have an extended battery life, supposedly having a sickening amount of life per charge cycle - but I'll never believe what a company has to say about battery life because its always wrong. Not to mention that the screen is longer, which makes the systems interface able to handle more things on the screen, which makes a better experience for gamers and other app users, even if its just for reading articles or magazines online.
The increased DPI and resolution could help set new standards in the mobile platform department, which would have drastic implications later down the line, AND its half the weight AND thickness of the iPhone 4S, despite being longer.
The drawbacks? Well, Apple releases have been... problematic... as of recently and they supposedly no longer support a YouTube App - although its available through Safari.
To a lot of people, myself included, this is not worth the price tag. I'm fine with my iPhone 4. Others are fine with their *insert phone here*. However, Apple has a cult of followers that WILL buy the product on launch because its a new iPhone. And they DID do a lot of nice things for it. Don't hate because its Apple, find another reason to hate them.