Hmmm, just to add to tghe general fray....
Since when have root logins not been allowed? It's not an option in the graphical login but if you use a text/commeand prompt login it still works.
I used to like it on Mandrake when you did log in as root and ran X that the default theme was RED, just to remind you, this seems to have gone.
If I am doing any kind of troubleshooting/admin work I have a terminal open where the first thing I did was run su - I can easily run anything with root priveledges from there, why bother logging in as root?
You can log in as root - if you know what you're doing - if you don't know what you're doing, you shouldn't be logginig in as root. I thinkit a very sensible decision.