Five reasons why iOS 7 will be a significant update.
1.John Ive And Criag Federichi Arrival
2.Next year expect iPad mini to get A6 and even iPod Touch , so they update iOS with even better features because I believe main reason this year iOS 6 was not so significant because iPod Touch and iPad Mini held back the update because they are both A5 devices being launched newly , they must have top notch performance , so iOS 6 wasn't significant.While apple also used Maps to show off A6 power over A5.
3.All Devices will reach 1 GB RAM and 512 MB RAM minimum , So AppStore also moves forward with more intensive apps and games.Since iOS update and devices launch around same time , I think it marks beginning of more powerful apps.
4.End of Jailbreak (Yes it can be possible because devs are scratching heads to jailbreak A5 devices on iOS 6 , so expect even less loop holes in iOS 7 and even if devs find a solution , it would be too late by the time they find exploit in all devices)
5.An exclusive iPhone feature like Siri with less gimmicks because of Ive but I think it will be significant because it will be used for differentiating 5 and 5S , which would also play a lot importance in marketing the new device.