In an op-ed in the NY Times, former baseball commissioner Fay Vincent (the last one who wasn't a lap-dog for the owners) writes an intelligent analysis of what's wrong with the umpiring in baseball and how to fix it.
Among the proposed changes: Increasing the pay of the umpires in the minors and providing retirement incentives to MLB umps to retire at age 55, allowing newer, younger talent to percolate to the top. Minor-league umps are like the baseball players of the pre-free agency period, earning so little in their occupation that a second job is required to make ends meet. When the umpires at the top level stay around well into their 60s, there is no spot in the upper echelon for the younger umps to attain. The combination of years of low pay in training and little opportunity for advancement to a bigger payday means that someone of talent might not consider this occupation.
I heard Vincent interviewed on the baseball channel on XM, and he mentioned that he was asking the owners and the umpires' union about this back when he was the commissioner. Nothing happened.