What would be your idea of a purpose for the "walk"? Why would we be gathering? An approximate location or venue? These are important questions to address early which will determine if anyone wants to show up.
If you have no purpose (education of the public, demonstration for or against something) then that's not much different than the OC breakfasts we already have on occasion. If I recall correctly, I'm pretty sure we talked about having an OC day at the park with a small table set up for handing out flyers to the public as an educational outreach.
Who's going to take the ball and make the event happen? You? Mark?:what: Someone else?
Now with all that said I'm sure there would be plenty of people interested in a get together and/or an organized demonstration. For me, I'd be game depending on the answers to the above.