(1) Yoko Shibui. Two things can happen. Her stated goal is 2;19;45, one second under Naoko's Japanese Record. I know for a fact that she is ready. If she tries to go with Radcliffe, and Paula runs outta gas, I think that Yoko can POSSIBLY win....just POSSIBLY. Otherwise, 2 things can happen. Yoko goes with Paula and Yoko runs outta gas at Paula's pace, then runs 2;22, a PR for Yoko. Otherwise, if she focuses on an even 2;19;45 pace, she CAN do it.
I can tell you this: Yoko is VERY feisty and firey. She is hella tough. I paced her on a hard workout and watched her training everyday for 2 weeks in Kunming.
(2) Masako Chiba: She ran 2;25 in Rotterdam for 2nd place on a rare warm day in Rotterdam. I dont see her running sub-2;20, but a PR and continued improvement would be great for her. 2;21-2;22 perhaps, if she runs intelligently. Then again, she has trained with Naoko here in Boulder, and has the best marathon coach in the world (Yoshio Koide), and she has run 1;06 for the half marathon, so you cannot really rule out 2;19 for her.
(3) Takaoka: He ran his first marathon (2;09;41) in Fukuoka last year on a rare warm day in December in Fukuoka. Given his 10km times, he should be ready for improvement to the 2;07-2;08 level at Chicago if he runs intelligently.