My phone already does what I want it to do, mostly, in terms of core features. Better battery life, thinner/lighter, faster, better bandwidth/latency, better camera, and a more ideal screen size, iterating meaningfully on all those areas at the same time is plenty.
I'm not sold on the screen width, though. I think it ideally should be a little wider. And I want better battery life; if I'm traveling and out all day I need to bring an external battery with me just to be safe, which negates thinner & lighter somewhat. At least it's better there than the 4S.
It's a sexy looking device. Very. I think this presentation, if anything, just needed a killer software update reveal to seal it. "Email is updated to take advantage of larger screen" is not something that even bears mentioning.