Smokey and the 3 Bears
This year, nearly all the talk about the minor leagues concerns one player, Rick Ankiel.  And with good reason.  He's about as good a pitching prospect as there has been in the past 30 or 40 years.  By comparison, Doc Gooden never had his control and Clemens was a full 3 years older at this level.  Taking it a step further, Ankiel's minor league numbers compare favorably to those of Seaver, Carlton, Palmer and Gibson.  Just 19 years old, he has smoked every level.  Currently, he's 3-1 with a 2.36 ERA and 60 strikeouts in 42 innings in the hitter-friendly Pacific Coast League.  His record could easily be 5-1 but the Redbird bullpen blew a couple of the leads he left them.  He's stifling batters to the tune of a .193 batting average.  This is after tearing a new orifice in the hitter friendly Texas league - 6-0. 0.91 ERA, 49 IP, 75 Ks, allowing only 41 baserunners.  About the only thing keeping him in the minors right now is his walk rate and the threat of Tony LaRussa blowing out his arm.
However, to paraphrase Austin Powers, there are three hitting prospects who put the GRRR in "swinger", baby, yeah, who might steal some of Ankiel's spotlight: JD Drew, Pat Burrell and Erubial Durazo.
JD Drew has been the talk of baseball for the past 2 years, but for very different reasons.  His well-publicized signing bonus spat with the Phillies after being drafted #2 overall in 1997, shackled Drew with an undeserved reputation of being a selfish player.  The unheard of demands of a $10 million signing bonus made by Drew's agent, the human anathema Scott Boras, alientated the Phillies front office and assured that he would not be signed.  What wasn't stated in the media was that Boras was trying to use Drew as a precedent setting case to abolish the amateur draft.  It didn't work and Drew paid the price by sitting out a year.  He did play in the independent leagues to keep the rust off, but he certainly didn't learn the kinds of things he needed to learn to thrive in the bigs.  Oddly enough, the Cards drafted him 5th overall last year and signed him for $7 million, making both the Boras and the Phillies look like buffoons.  But enough gossip.  JD Drew can play.  Injuries have camouflaged his talent so far this year, but both scouts and media types gush when they see him play.  He should be up with the Cards by the All Star break and produce a decent second half and a fine career.
The Phillies tried to atone for the Drew fiasco with last year's #1 overall pick, Pat Burrell.  The results so far look pretty good.  Burrell adjusted to the wooden bats nicely in the Florida State League last year, hitting .303 and slugging .530.  Apparently not satisfied with just being good, Burrell decided he needed to destroy a league and picked the AA Eastern League as his victim.  Long considered pitcher friendly, the Eastern League has suffered under the Burrell onslaught - he's hitting .340, slugging .609 and getting on base over 46% of his plate appearances.  Once he gets to the bigs for good, which could happen as soon as this September, he and Scott Rolen will make up one of the better corner tandems in the NL.
Erubial Durazo came to prominence recently when he was promoted from AA El Paso after hitting .403 in 226 ABs.  He had scored 53 runs and drove in 55 on 91 hits, 35 of which went for extra bases.  He also walked 45 times while striking out only 35.  Well, he's only gotten better in AAA.  He's hitting .486 with 5 homers in 35 ABs for Tuscon.  So where did this guy come from?  For those of you who follow the winter leagues, you got the heads up on him long before spring training.  He played in the Mexican Leagues, where he hit .345 in 223 ABs, driving in 48 and scoring 51 times while showing a great eye for the strikezone.  Of his 77 hits, 34 went for extra bases.  Durazo was signed by the D-backs this offseason and is currently blocked by Travis Lee.  But 24 year old hitters this good find a way to get major league at bats, either by trade or position change.  I seriously doubt either Tony Womack or Bernard Gilkey will be able to keep this guy out of the line-up if and when he gets the call.
Other hitters who are making big noise are Jay Payton (AAA, Mets), Daryle Ward, (AAA, Hou) and Milton Bradley (AA, Mon).  I also think Aramis Ramirez will be terrific, but he doesn't really qualify as a prospect anymore, since he's already had more than 250 major league at bats.