For those without a little bit of NT history, there has always been an administrator user. As most of you have witnessed with XP (which is NT 5.1), you set up the Admin credentials (password and such) during the install.
In most, if not all cases, you are heavily urged, if not forced, to create another account. The original idea is that this user account is for day-to-day use, while Admin is reserved for special cases. Granted, this paradigm makes more sense in the business world, but doesn't do much for home users or systems with only one user. So, MS chose the path of making your one user an administrator as well. Just think of this as if it were WIn9x/ME, where any user can do any and everything to the system.
PERSONALLY, I am a heavy user of Win2K, BUT I DO NOT USE an administrator account in a day-to-day fashion. Sure, it is nice to have, but I really don't need it. But when I do need it, I can either log in as admin or temporarily do so with the "Run As..." service (hold shift and right-click on any executable or shortcut to an executable). This methodology FORCES me to consider my actions before doing something so serious to the system that it requires admin privileges. Stability is the name of the game with NT, so you don't just go around giving everybody full access.
So, what does SUO use? A power user is perfect for 99% of the things I do. I've even forced my XP install to have the lone admin and one power user.
-SUO