Stock dropping, really? He's 19 and is holding own in a pitcher friendly A- league. He's hit 20 home runs already. Yes, he's striking out a lot and isn't going to progress through teh system quite as fast as the optimists had hoped, but this hardly means his stock is dropping. I'd also note that despite the .050 point drop in BA from Elizabethon to Beloit, his OBP has remained the same, which means he's taking A TON more walks... My guess is that he's probably letting a few too many called strikes go by, which is far easier to improve on than simply flailing away at pitches out of the zone.
I could see making a case that Arcia moves into the 1 spot simply because he's performing quite nicely at AA as a 22 year old, but that isn't because Sano is less of a propsect as much as it is that Arcia is becoming a nicer one, but let's be sensible. This kid has Miguel Cabrera potential, and that hasn't changed. Would I trade him for the right package? Sure, but those deals never happen.