We will probably have about 500 people in line at one time MAX. I can't imagine more people than that showing up early enough to be in line at the same time.
However, we haven't had our dry run with the new database yet.
One hour through the line sounds like a good estimate for how long it might take if you're there Saturday Morning at the end of the line. Everything will be streamline this year and the fact that we know WHERE the lines go this year should account for a lot. Half of the convention has already pre-regged, so they'll be in another line already.
Also, the Door Reg line will be in the shade this year. So you shouldn't have to worry about heat exhaustion and dehydration.