Thanks to "birob" making the suggestion on the July 15 Gameday Thread, I decided to take on this mini-project of putting all these mini-lists together from the four major sources (Law, BA, Sickels, Fangraphs) and create a combined list, averaging each rank and compiling them into one large "2012 Mid-Season Top 50 List" from all sources. Of course, there are a few difficulties along the way in creating such a list. John Sickels ranked guys like Rizzo, Simmons, Bauer, Grandal and Pomeranz, who were excluded from the other lists due to them being in the majors. Instead of just eliminating these players, I also bumped up the likes of 5 players from 51-55 on John's list to make up for it (because he had a full 120). Keith Law included 2012 Draftees (Correa, Buxton, Fried, Zunino, Almora), in which no other source did. At this point I had no other names to add to the list (he had a straight top 50) so I instead bumped up his players to #1-45. Due to these restrictions, all 10 of those players were excluded from the "official" list because only one of the four sources had them eligible. Otherwise, the fun part ensues. There were 60 "eligible" player ranked, and they are below with the average of the four sources. On the bottom you can find the link to the public sheet with Best/Worst, Std Dev, and the raw data.
For any unranked prospect, I had a "rank" of 60 for the lists they did not make.
4. Keith Law Top 50*
*Can be found on Insider on ESPN, as well as in the comments section in the link