Accept anonymous submissions. Encourage notes via e-mail, intranet, or website. Review last year's meeting feedback. Circulate a statement of meeting goals and objectives . This will reinforce your position, and flag you as someone to watch.
People hate defining goals and objectives.
You can always change your mind later. No one will remember what you said by the time the meeting takes place, anyway. Be careful about advance publicity. Don't start taking credit for a great meeting until you've had one. A glowing preview in your company newsletter will surely backfire if your meeting does.