I'm planning to be there, assuming nothing comes up. If my regular group is still gaming that evening, I'll only be around for the morning, otherwise I'm tentatively planning on both sessions. Now that a definite date has been chosen, I've sent an email to the rest of my group and some may attend.
BTW, since plans change constantly, any "hard count" will be somewhat inaccurate. That said, I agree it would be useful to try to nail down a good estimate of how many will attend each session. Also, a few questions:
1. Are you planning only 3E games, or other systems?
2. If other systems, are you assuming the participants already know the system, or will some/all these games be for newbies wanting to try something new? (Mutants and Masterminds jumps to mind - I've never tried it, but all the reviews have raved about it).
3. Do participants sign up ahead of time, or just join a game as they arrive? I'm not suggesting making this as formal as GenCon, just getting a feel for how you're planning to run things.
Thanks for all the hard work you guys have put in.