It will definitely be worth watching a live stream, or at least watching the video back at some point. Seeing the UI in action is a lot better than static screen shots.
If the main pillars of the new experience are a flat look, content before chrome, bold colours and typography with a focus on motion and activity, then unfortunately it will be little more than a rip off of the Microsoft design philosophy.
As a tech fan, I really hope they don't go down that road. The last thing I want to see is platforms converging into one homogeneous gloop. Part of me wishes they would stick to their guns somewhat with regards to the 'skeuomorphism' thing. I don't think many people will miss stitched leather effects in their apps, but certain metaphors like a compass or sticking a pin in a map, buttons, switches and dials looking like (shock horror) buttons, switches and dials, is not inherently a bad thing. They just aren't en vogue.