There are 13 pitchers in the majors, out of the 127 who've thrown more than 100 innings, who average less than 88 MPH on their fastballs. There are just 4 who average less than 86 MPH, or basically throw as hard as Milone.
Those four are Jamie Moyer, Livan Hernandez, Mark Buerhle, and Barry Zito, who I would argue are some of the greatest "pitchers" in the majors right now (pitching, I would argue, is a matter of your results relative to your "stuff").
All I'm saying is that to succeed, Milone likely has to be a guy with that type of deception, command, and intelligence.
Not impossible, just not likely. It's more likely he's one of the many guys who can dominate minor league hitters with command but won't be able to strike out enough guys or prevent enough homers to succeed in the majors.