I went out yesterday for a nice and easy 4 mile run, and had absolutely no foot pain. When I got home, I made sure to stretch for a long time and ice the foot a little. The real test was this morning to see if there was any residual pain. I'm happy to report that I am up and walking around this morning with no pain whatsoever.
I am going to go out again late tonight and try for an easy 6, and see how I feel, but it appears that I'm ready to ease back into my full running schedule again.
...This means Leadville might still be a real possibility.