Read some other posts and it seems like its pretty reliable that there are fewer regular ticekts than seats and standbys will indeed get in. It's just a matter of how many standbys. My conclusion would be that yes, you can show up anytime before 6am with a regular ticket and get in with out a problem.
One other thing. They began at the front of the line at 6am to give out wristbands(which are also numbered by the way and that is your order for the rest of the day) and order of arrival numbers. People with regular tickets/wristbands were told to be on the studio lot at 7:15am. I've got to imagine if you're in the back of the line, that by the time they get to you, you won't have much time to leave and return. People at the front have a while since they get their wristbands right away. So if you plan on getting there later and being in the back of the line, also plan on going straight in.