Omar Poveda of the Jacksonville Suns has a big looping breaking ball that he can both throw for strikes and throw low to get hitters to chase (Kentrail Davis looked pretty comical trying to hit it). His fastball isn't overpowering, but it is hard enough and has good sinking action.
Josh Stinson in the Brewers system (already on the 40-man) has a 2-seamer with a ton of movement, a mediocre 4-seamer, with what looks like a slider. The slider he only threw occasionally in what I saw, and he didn't look like he had good control of it. The 2-Seamer wasn't exactly going where he wanted to either, but if he harnesses that pitch with any kind of consistency, the big pitcher could break a lot of bats and be successful.
Daniel Nava for the Pawtucket Red Sox looks absolutely silly on curveballs, while Jose Iglesias showed some plate discipline when I saw him (although he may have been too patient as he took a 1-1 fastball down the middle).
I watched Aaron Cook pitch, and he was throwing an 89 MPH 2-seamer that has some movement, but not a lot.
Pat Misch of the Phillies AAA team threw a bunch of breaking balls early on when I saw him, with a soft fastball. The lefty got a fly-ball, ground-ball, infield fly-ball, hard hit ball in the infield, ground-ball, line drive, and a strikeout on an outside fastball.
Chris Schwinder of the Buffalo Bisons (the Mets AAA affiliate) had problems getting his curve down, but it looks like his fastball has good movement and decent velocity.
Daryl Thompson of the Rochester Red Wings, the AAA affiliate of the Twins, has a slow curve that would make most Korean pitcher blush. The fastball provides some nice speed differential, but he doesn't seem to have much control of it.
For the Greenville Drive (in the Red Sox organization), Keury De La Cruz plays a good left field despite not having superior speed. His arm is very pedestrian though. Yeiper Castillo has a nice breaking ball that he can throw for strikes and get swing and misses with.
Wes Benjamin is a lefty freshman starter for the University of Kansas. He isn't even close to what you would call overpowering, but his arm angle gives him some interesting movement. He was leaving the breaking ball up, and really had control issues. He walks way too many batters, but he doesn't give them a lot of good pitches to hit. He looks like a ground-ball type pitcher.
Robbi Rea of Oklahoma State plays a decent 2nd base, and has good plate discipline with really long at-bats with fouls that lead to walks.
Dallas Beeler for Tennessee Smokies is a tall right hander that keeps the ball low for the most part, with decent velocity and some movement on fastball. He doesn't seem to have a great feel for his breaking pitch, but it is a big dropping curveball. Also throws more of a straight 4-seam fastball that has good velocity that he likes to keep away from righties. He seemed to be throwing a lot of pitches down the middle of the plate and really developed control problems as the game went along. He looks to be a good fielder of his position.
Nick Struck of the Smokies has a big looping breaking ball that breaks to the left, but he can't really throw it for strikes. If he ever gets to where he can, it will be a really nasty pitch. He also has either a splitter or slider that is sort of a weird pitch, along with a moving fastball that he can throw for backdoor strikes. His 4-seam fastball has some nice velocity. Casey Weathers had no real control at all when I saw him, with a ton of wild pitches and walks.
Alberto Cabrera of the Smokies has a hard moving sinker with a hard breaking ball that possesses a lot of break but not much control. Stuff isn't the question with Cabrera, control will be. Also has a nice little curveball he can break out for speed differential.
Rebel Ridling is listed as a first baseman for the Smokies but played left field and doesn't have the arm to play there. Mike Burgess for Tennessee Smokies can run reasonably well and drove a pitch low in the strike zone. Defensively, he has a good arm.
Wellington Castillo of the Iowa Cubs has a violent uppercut fly-ball type swing. Adrian Cardenas drove a ball really well, but he is not a great runner. Anthony Rizzo brought up questions about contact and bat speed with a big hack and miss. Ty Wright has a big swing but can make contact on offspeed pitches. He also seems to have decent speed as well.
Bobby Wahl of Ole Miss has 88-91+ MPH straight fastball. Hitters were really late on it but location wasn't always great and really faded. His 73-78 MPH curveball can be throw for strikes and get swing and misses, and he kept it away from righties. What I found concerning was that his velocity dipped rather early in the game and didn't come back. This could simply mean he doesn't have a great amount of arm strength built up, which isn't concerning at all, or he could just have to put a lot of effort to get the fastball up at its peak, which means he should be a reliever. Worst case scenario is that there is some kind of injury there.
At Ole Miss Alex Yarbrough is a great fielder at 2nd with the arm, range, and everything you look for in a middle infielder.
Georgia Michael Palazzone: It is hard to excited about a right handed pitcher who is hitting 85 MPH on the radar gun but he has a big looping curve (sometimes under 70 MPH) he can throw for some quality strikes. Also has a change-up at 78 MPH. That pitch is not near as good.
Peter Verdin (Georgia) nice double on a breaking pitch that stayed too high. He is a pretty good runner too. Kyle Farmer for Georgia has range, but the arm isn't great. He can run okay.
DJ LeMahieu Colorado Springs AAA, late on fastball in first at-bat, but pounded a 3-1 letter high fastball for an extra base hit the other way. Tim Wheeler made a terrible throw out in right field, but drew a couple of walks. Andrew Brown seems to be having contact and pitch recognition problems.
Christian Friedrich has a decent 90-94 MPH fastball with a curveball that looks like it could be a good pitch. He was really fastball heavy when I saw him, but it seems he can locate it well other than a few he placed in the heart of the plate.
D.J. Mitchell of the Yankees AAA has quite a bit of movement on all his pitches, including a slider and a curveball. He doesn't have hardly any control at all of those pitches, but his velocity seems adequate.
Jason Bulger has a decent loop his breaking ball, but can't really locate it well from what I have seen. His fastball really isn't very good. Chris Dickerson covers a lot of ground in center field.
Jeurys Familia of the AAA Mets, has a hard fastball that he can throw both low and high. Jeremy Hefner has sinking action on some of his pitches with an occassional curveball. The tall right hander throws high fastballs and is pretty athletic.
Scott Rice of the Isotopes (Dodgers' system) is a big lefty without great velocity. He was having a lot of problems with his breaking ball command. Josh Fields has a nice looking power stroke, and he hit a ball for a homer.
For Creighton University, Kurt Spomer has decent 2-seamer velocity for a side armer. He struck out hitters from both sides of the plate when I saw him, which may suggest that he isn't strictly a platoon pitcher. Mark Winkleman has a hard moving breaking pitch that he was able to keep low to go with his curveball. Jake Peter showed off some great defense at 2nd base.
Greg Reynolds from Round Rock has a nice breaking pitch with plate to plate movement that he can get for called strikes. Even though he broke a bat, he gave up some pretty hard contact. Tommy Mendoca struggled on a play at 3rd base, while Julio Borbon looked awful out in centerfield (but this is something we already knew).
Casey Fien in the Twins AAA has no real control of is breaking stuff (even though it has a big drop), even though he threw one good one low and outside. His fastball was staying in the middle to high middle of the plate without much velocity.