It's kind of unclear atm. Holland seems to be gifted and will most likely be a second or third line center, but will never be first line calibur because of his inconsistency issues. He had a pretty explosive few games in the AHL, it was good enough to get an NHL callup in the playoffs (he didn't play any games). Of the three he's got the biggest bust potential. But I doubt he's gonna fully bust. I believe he will contribute to the NHL at SOME level.
Palmieri is doing all the right things in the levels just under the big leagues. He was pretty great in the AHL and he was a star for USA at the WJC. But he hasn't got his game figured out for the NHL level. He could fit in and keep up at that level, but he's got some time before he excels. Just like Holland, he'll never be a first line guy, but I'd say he has more potential than Holland. At best a second line 60 point guy. But that's after a few years in the NHL. He'll start as a 20-30 pts a year, and if things work out he'll turn into a star. Of the three he's the most likely to have the biggest impact.
Etem...it's hard to critique him. I'd have to wait for his AHL days. He's got natural scoring talent, and if I had more to go off of, I'd say that he could be the best of the three. But I don't. He's speedy, he can score, he drives to the net, and his drive to succeed is extraordinary. Plus it helps that he was drafted by a team in his home...area. That's extra motivation. One thing that bothers me from what I saw at training camp is, despite his speed, he has a very strange skating stance. He hits his strides hunched over. And while this provides lots of speed (i know because when I skate and I need an extra burst of speed I do the same thing) it makes him very open to crushing hits. I'll see how his game translates to the professional level before making my judgement. He is our first ranked prospect.
One guy from Anaheim worth being excited about is Devante Smith-Pelly. If you followed the OHL and CHL finals, you'll know that he was a playoff hero for the Mississuaga St. Micheals Majors (longest name ever). I got to actually watch a lot of those games, and we got a total steal in this pick. If I was Murray and I had picks 12, 28, and 29 last year I would have made the same first three picks. He has natural offensive talent, vision, and hockey iq. He can score, he can pass, he can skate, and his defensive game is so solid, that I believe that with the right development he could go back in time remove Travis Moen from Anaheim's checking line in 2007 and improve it. At the NHL level I see him being a prototypical Sammy Pahlsson, meaning his checking game (which he decided to work on) will be at the same level, or better, and he'll add even more of a scoring touch. Think a combination of Pahlsson and Big Buff. I've seen him play 10 times and I've been left impressed each time.
Hope that helped.