You can set Windows Update to download updates but let you choose whether to install them.
I think this is the booby trap alluded to above when you innocently try to reboot or shut down the system. If you're not paying attention, you miss the correct option of "do it right now" and end up with the default option of "once I've installed this lot".
Win7 is a lot better than XP regarding admin privilege and general locking down of the default security.
...that way we might finally start seeing certain software that runs correctly without requiring admin rights
Yes, that too. I admit to being caught once, in that I was asked to write a program that stored a bunch of stuff in the registry (so the user couldn't easily manipulate it). This was fine on XP but then MS seem to have properly restricted write access to the registry and it didn't work on Win7. Linux never had the concept of a registry, it's all done with random text files so it's easy to look for a per-user config. That seems to be the new MS model now, too.
I remember back in the day thinking that the MS devs should all have been given weedy machines to work with because it would have given them more incentive to make the code efficient and run at a decent speed.