Here is an interesting thing that Taveras' success (and Eschelman's to some extent) has started me thinking about for yet another time.
I really believe that most baseball fans, myself included sometimes, exaggerate the difference between levels in the minors. I think most of the difference is adjustment (and adjusting back), and that basically, players who are having success in Lakewood and Clearwater could very well succeed just as frequently in AA or AAA. We always talk about more junk-ballers and more "pitching backwards" in AAA, but I attend games at Reading, Lehigh Valley, and Lakewood, and I honestly don't see it. A lot of low-A pitchers can snap off a pretty sick curveball, and they throw it for strikes more often than we're led to believe. And, the same for pitchers facing minor league hitters...I hear announcers say "he won't get away with that hanging curve in the big leagues, MLB hitters will crush it", yet I see great hitters pop those pitches up, or pull them foul all the time in the big leagues, just like they do in the minors.
I think we're perpetuating a mythology about the minors; I just wish there were a way to exploit the mythology for competitive advantage. The steps up the ladder just aren't that big.
Of course, a lot of the players believe this, which causes it to be somewhat of a self-fulfilling prophecy, and it sure is in the interest of big-leaguers to perpetuate that belief...