Ryan Hall is seriously diluting himself if he ever thinks he'll get close to that again. Just thinking 59 flat ain't gonna get you there pal. I hate to say it, but he's done. He'll never get back to the form he was in when he ran his PRs. The I think it would take 2-3 years of solid track focused speed work, refocusing his energy back to the 5k and mile to get back to where he was.
Ryan did so well in the marathon early on BECAUSE his focus was on the short stuff and his stride and muscular was geared towards pop, quick turnover, and efficiency. This, however, was built up from YEARS of mile specific work. That's his only shot at getting back on top. Regardless though, he'll never even come close to breaking 60 min again, let alone 59 flat.
POSITIVE thinking is good, but LOGICAL thinking is what makes the positive goals reality.