UAC shouldn't be ditched, but it could perhaps be implemented in a somewhat less intrusive way - like keeping you elevated for a (short) period of time, instead of requiring elevation for every action. But returning to the old days of everybody's-a-friggin'-admin? No. (And yes, UAC currently can be annoying, especially if you're in the process of setting up a new computer and it hasn't occurred to you that you can disable UAC temporarily until initial setup is done...)
With 7, MS ought to drop 32bit versions of the OS completely - and IMHO they should've done that already with Vista. I know, it would have pissed off a lot of people, but if you keep clinging on to legacy, you never really move forwards, and there's no real incitement for developers to learn how to write 64-bit clean code.