Well, just quickly off the top of my head.
#1: Unified notification center. So when I read something on one device, all my devices register it. So let's say I clear off an iMessage on my iPhone, it clears it from the iPad and computer. Same with emails, etc. I shouldn't have to clear each one individually, effectively doing the same thing 3+ times.
#2: iCloud that actually works properly. iLife and iWork should have complete feature parity across platforms and sync all files without any loss of data or functions, all seamlessly. Similarly, iBooks and Preview should be integrated and my pdfs and ebooks should sync across all my devices, keeping my notes, bookmarks, etc. in sync. Again, similarly, my podcasts, itunes U, etc. should sync across all devices and look the same.
#3: Unified Safari. Safari should be updated to include all features on the full-blown version. I.e. extensions and other features like better cookie and plugin management (think white lists) should be added into mobile safari and the full safari. Next, all history, bookmarks, keychains, etc. should be synced across all devices.
In short I want a unified experience no matter where I am interacting in my Apple environment. I want to pick up where I left off, no matter what device I happen to pick up, so that I can focus on my actual work and stop wasting time trying to keep everything configured and in sync.
