Here's a bit of what Mayo had to say on each:
Danny Espinosa: "A shortstop for much of his pro career (and at the infielder factory that is Long Beach State), Espinosa played second every day in Washington last September. That could very well be his job to lose this spring, though he does have the defensive ability to play both middle-infield positions. Offensively, he's got some speed and power and was one of the few 20-20 guys in the Minors in 2010."
Bryce Harper: "Harper has as much raw power as anyone who's come around in a long time and the skills to tap into it to all fields. He's got such great bat speed that he should hit for average as well. He runs well for a guy his size and should be a very good right fielder with a plus arm when all is said and done. All those tools combined with an all-out attitude should spell quick success for Harper."
I think many Nationals fans were surprised that anyone was ranked higher than Harper on the list of outfielder prospects, however, I think they were shocked it was by a kid only a year older than him. To Mike Trout's credit, he is quite a ball player. In A ball at the age of 19 the outfielder batted .362/.454/.526 with 45 stolen bases and 76 runs in just 81 games.
However Harper has been so hyped that many of us have laid our collective hopes for the future in his and Stephen Strasburg's hands. Picking Trout in this situation was the safe pick here, he has two years of MiLB experience to pull from while Harper has only a good Arizona Fall League showing. Trout is under less organizational pressure from his team to make it to the majors because Anaheim is in less of a organizational crises than Washington. Lastly, by picking Trout, Mayo doesn't have to answer any questions about falling for the Harper hype if something happens and he busts.
I can see where Mayo was coming from, and I don't agree with his reasoning. We want Harper to not be the best in the minors now, but be the best in baseball tomorrow.
Espinosa's presence on this list, as well as Norris and Ramos' are a strong manifestation of the Nationals improved minor league system. In the past, we would be psyched to have one minor leaguer who was good enough to be considered on any of these lists, now we have at least four.