Quote:
In the one Vista installation I've dealt with, an LUA account did seem to be the default.


For the first account on the system, it's not. It appears to be on the surface with the UAC stuff on (allow/deny), but to the system, your account is an admin. UAC simply tries to put barriers at all the critical points to stop something bad from happening. If Microsoft misses a hole with the UAC barrier, malware could still exploit the entire system from the default account Vista creates. A true LUA account with UAC would not only see the allow/deny prompts, but also a username and password prompt to provide an admin password.

Now if you go to the User control panel and try to make a second account, the default selection is indeed in Standard User instead of Administrator. But this is the same going back to NT if I remember right.

"Run as administrator" with an admin account provides that false sense that there is actual user separation going on. Only LUA provides that.