They need live icons instead of a static grid. Swiping through pages of icons is fine, but that should be a secondary app search feature, not the main way of going to your primary apps/notifications. Notifications and favorite apps should be integrated together. So far only Windows Phone does this well. Apple is slow to change, or at least slow in this mobile market. Which isn't good when newer/improved OS' are popping up now (Ubuntu, Tizen, Sailfish, BB10, etc) which have fresher takes on various features.
Also the design scheme seems a half-hearted attempt at it, and it looks like they borrowed design cues from 5 years ago. Too much in the way of transparency and pastels when they should have gone for cleaner, darker, and better contrast. The metallic/shiny elements from the original iOS/iPhone has not aged well, and it really has always looked a bit tacky on a screen (akin to overusing gloss, which Samsung does on the hardware side of their phones - it must be popular with some people, but I don't like it). Definitely looks like they copied elements of Linux or stock Android, though possibly not deliberately (designers don't entirely live in bubbles). The design is flatter, but it's not the Swiss kind of elegance that Microsoft and Apple love to talk about these days. It's clear they were going more for a futuristic but bright look. Or clown chic, perhaps.
Live wallpapers are annoying. They look pretty, but are as useful as the skeumorphic stuff. Nothing new, even Vista had DreamScene. Zero appeal to me, don't use live wallpapers on my Android phone, either.
Overall, I don't like the new look. It looks like a halfway measure, and I'd much rather see what iOS 8 looks like. It might be mean to call this Apple's Vista, but if I were currently in the iOS environment I would wait a generation to upgrade. Apple seems to be "innovating" (really it's just changing) to appease the public and investors who are worried, but really they are afraid to break what isn't broken, and it shows. It's not garishly or hideously ugly, but it does look like they cobbled together two different UIs, and it's not polished (so to speak; don't literally want to see polished surfaces in the UI ) at all. Very inconsistent looking.