My plan right now, since I'm totally fine walking. Is to work on getting to a place where I try to run/walk 1/2 of it... and then totally walk the rest. I should be able to maintain less than the required 16-minute per mile pace that way. On the other hand, if I can't maintain it, I'll be picked up by the slow bus.
I'm also thinking about seeing if I can come up with some kind of running shirt that has the slow moving vehicle triangle on it with a Tigger Tail and the word "Injured" across it. :-)
The truth is that instead of treating it like a race, I've started to think of it as a fancy place to get in some physical activity, rather than pulling out completely.
Does that make sense?