The theatre is big, 3051 seats according to the convention center's website, but it could still easily fill up if the response is actually as strong as was indicated at the Masquerade when the MCs asked how many people were planning on going to the movie. The movie is at 1, so the line might very well start forming at 11 or 10, and the exhibition hall doesn't open until 10 and closes at 3...
If other people i know are going to the movie i definitely want to go. If they aren't, well, there have been a lot of other movies i wanted to see in theatres but not been able to get a group together for and as such have missed out on them completely until they're out on DVD. (And i haven't had much luck getting people together for DVDs either, so...) Going with a whole lot of con attendees isn't as good as going with my friends, but it's certainly a far cry better than going by myself since i feel significantly more social connection to fellow con goers than to a bunch of generic strangers at a normal movie theatre.
Edit: It's currently at 67% on RottenTomatoes, which is better than i had been fearing. Looks like the bad reviews are "this movie has an incoherent and sucky plot" and the medium to good reviews are either "no one but fanboys will like it" or "OMG! Giant robots! Explosions and stuff! Who cares if the plot sucks?"
The most amusing one to date is "Has Hell actually frozen over? Are pigs now taking to the sky? I only ask because Michael Bay has achieved the unthinkable: he's directed a crushingly entertaining movie." :) Which is a little unfair because i liked "The Rock," but between then and now he's also directed Armageddon, Pearl Harbor, and Bad Boys 1 & 2 =P
So it looks like i am sufficiently forewarned to be able to actually enjoy the movie if i do go :)