Hmmm...
My first thought is that this trade doesn't work with the pick. Orlando is giving up too much, and the Suns are getting too much. Take away the pick and the values add up much better.
Orlando's roster is kind of a mess after the trade. With Drew Gooden, three of the Magic's top four players are forwards, and the Magic will have to play an undersized PF pretty much all of the time. Their draft pick would almost have to be Okafor, he'd have to play exclusively at center, and then the team's entire front line is undersized.
Without the pick, I don't think Phoenix upgrades their roster. Juwan Howard is only effective at PF--that's something he proved last season. Since the Suns have three PFs already who need time (Amare, Lampe and Zarko), the only way Howard gets on the court is if one or two players are playing out of position. Howard would be worth more to the Suns IMO if he was moved along immediately for a shorter contract.
With Artest, a lot of his offense comes from post-ups, which wouldn't fit nearly as well with Amare's game as it has with Jermaine O'Neal's. Then you've got the head-case stuff, which pops up at the worst possible times and also worsens the team's overall chemistry. Also, Artest likes to take over the game at times, and I don't mean that in a good way; if he's installed in Phoenix as the third option with a chance to move down the list, there's going to be trouble at some point.
Artest might be a comparable or even a slightly better player than Shawn Marion, but my guess is that this Phoenix Suns team is better with Marion than they would be with Artest.
From the Suns' perspective, then, this is a salary dump, and I think the timing is very poor right now for that kind of move. If the Suns aren't improving rapidly next year, there's a danger that they'll collapse entirely into a Bulls-like or Clippers-like morass, and the easiest way to keep improving is to keep the team's main pieces together.