For all those who are speaking as if this is Dickey's first year being solid, I would like to bring up his numbers since joining the Mets in 2010.
2010: 2.84 ERA, 1.19 WHIP, 104 Ks in 174 1/3 innings
2011: 3.28 ERA, 1.23 WHIP, 134 Ks in 208 2/3 innings
2012 (so far): 2.20 ERA, 0.94 WHIP, 90 Ks in 90 innings
Before this year, the only thing that was holding Dickey back from being a very solid fantasy pitcher was his strikeout rate, which has skyrocketed this year due to an unbelievable swing and miss rate. His walks are way down and his strikeouts, as well as his swing and miss rate, are way up. One thing that we have to remember is that we can look at Dickey has a "young" pitcher even at 37 years old, as he just recently started throwing the knuckleball. This looks to me like a guy who is finally putting it together and is becoming more comfortable with his "stuff". Also, for those who don't get to watch a ton (or any) Met games, understand that Dickey actually throws two different knuckleballs: He throws a slow knuckleball in the low 70s and then a knuckleball in the mid 80s as well. He has the best location that I've ever seen for a knuckleballer, and even when the ball is over the plate, his ability to change speeds with the knuckleball leads to guys swinging and missing regardless.
That being said, Bryce Harper is obviously an immediate 5 category player in fantasy and is a great young player; but in a non-keeper league, I would feel comfortable making this deal especially considering the other bats that you'd be able to plug in after dealing Harper.