Since 2008 I cannot recall many obvious aesthetic changes in a beta program. I think the design is baked in.
To those who say - "If you haven't seen the WWDC session videos you won't get it!". Stop drinking the cool-aid. How many end users will have seen those videos?
Each year I run through the WWDC session videos and they get me pumped. Not only is the content great but the Apple Devs are generally captivating. This year is different. If you're a dev go check out the "Building User Interfaces for iOS 7" session video. Dear God! The main speaker is so uninspiring, dull, and monotone you will struggle to get through it. Additionally he provides not nuts and bolts detail whatsoever. What has happened at Apple?
iOS 7 is currently a train wreck. When John Gruber starts linking to (genuine) criticism you know you have a problem. The basics are wrong. How can you apply grid based design techniques to an area of one centimetre square? The retarded re-introduction of transparency everywhere - Vista 2.0. It all looks so - dated.
Taste, as opposed to fashion, is an innate quality. Those without taste will watch the WWDC video, swallow the line they are being fed and follow the party line. Those with taste will retain a capacity for independent thought and critical evaluation.