I don't think Apple didn't consider changing the OS to work specifically for the tablet, they thought that it was more important to have a unified user experience across all their iDevices. And as long as they keep making apps, like The Daily, that are designed specifically for the iPad, I'm fine with the iPad sharing the OS with the iPhone. Well, the notification system needs to be improved -- it shouldn't pop up in the middle of the screen, and there should be a way to review old notifications, not just see the one latest alert and then it disappears forever. But that doesn't have to be different from the iPhone.
I still believe Apple did not put a LOT of work into a new tablet UI for 2 reasons, that are both the same really.
1: They had no idea the iPad would be a success, so why invest your company totally into something that may be a total flop as virtually all previous tablet had been.
2: The did not wish to frighten away their loyal customers, not the tech customers, but the guy in the street ones with something too new, they needed him to see the iPad UI and understand what it was as it was the same as he'd seen before and not be frightened of it and not buy it, again, causing the iPad to flop again as another techy thing average consumers just did not get.
Basically, Apple put as little work in as possible and also wanted to keep it dumbed down at the same time.
Ensuring if it did flop, minimum damage, at the same time making it simple so hopefully people would buy it as it was familiar to their phone and touch from Apple.
Ok, job done, market established.
Only problem now is, they are stuck with it.
Do they now make it more advanced and confuse the people in the street who are not "into" computers?
Or do they keep it dumb and frustrate those who want more?
It's almost like they had to step back a long way for product No.1 to give it best chance to work, but not it's worked, they are stuck in the past, and how do they get themselves back to today with minimum damage?