Webb's 5k progression in 2004-2005 was 13:45, 13:30, 13:10. He ran 13:30 in the spring of the same year he ran 13:10, which was run at the end of the summer.
I think Salazar could amaze us with what he does with Webb, and by amaze, I mean get Webb to run 3:29, 7:32, 13:00. I don't think Webb will attempt a fast 10k for a long time, and if he does run some longer distance races(8k-12k), it won't be so much for time as it will be a training exercise like Steve Scott use to do. Salazar has already said he's not going to have Webb lifting any weights for the next 6 months. He said Webb needs to lose the bulk. My thoughts are Salazar is going to have him return to a primarily aerobic base, getting in a lot of easy miles and maybe getting back into some xc races in the off-season.
Webb hasn't lost his speed- he's lost his speed endurance. I think Salazar will help Webb find this endurance and we could see a much more fit Webb than we've seen in the past. I only say this because of what I've seen happen with Rupp, Goucher, Begley, and now Ritz. I think Salazar already sees coaching Webb as a mighty challenge, especially now that he has so many athletes under his wing, and athletes that need constant, close attention. He's basically coaching the best distance runners in America: The AR holder for the mile(Webb), the AR holder for 5k(Ritzenhein), the AR record holder for 5k indoors(Rupp), the top 10k female runner(Yoder-Begley) and the top female marathoner(Goucher).