"Add User" step is impossible to skip in the current version of the installer, even when doing "Custom Setup". The reason I wanted to skip "Add user" is that we are using NIS and, as a result, there is no need to have any non-administrative local accounts.
Yes, you can skip the add useer step, just click on "Next" in the GUI installer after providing the root password. If you are performing a text install, then just select "OK" at the Account Creation screen and you will be able to get through it. We made it appear that it was a necessary step as we really want people to create user accounts and not use root as the primary account on the machine. The only reason not to create user accounts would be the reason that you found . . . NIS :-) Sorry for the confusion.