Taking a look at the recent mlb.com prospects page makes you wonder. Hmm, both 6'5" and 220+, and in pictures from their State College days, they look like twins.
Nick Kingham grades out as having an above-average major league fastball right now with off-speed pitches that are below average now, with the potential to be above average. While his overall numbers were uninspiring, he did have a 1.68 ERA over his final nine starts. He has a nice clean delivery, as this video shows.
Holmes gets slightly lower grades for potential. As several have noted, his numbers at State College were odd. They featured 5.31 hits per nine innings, 0.15 home runs per nine, 4.40 walks per nine, and 5.16 strikeouts per nine. It would seem that some mix of a sinking fastball, a shaky change, and uncertain control might get you to this picture. This video from State College shows a more funky delivery for Holmes.
Having established that they are different people, my question is, "What is it about Holmes that makes so many consider him a top prospect?"