I think Amare has always had a knack for passing, but he has never really been a consistent (or, to steal a phrase, "willing?") passer. He's always been able to deliver passes in traffic right where you'd want the ball to be thrown if you're the guy on the receiving end. However, he has always been extremely myopic offensively. Whenever he delivers a beautiful pass, if you watch his eyes and the way he executes the play, it is his first option to pass on that particular play from the get-go. On most occassions, it is his first option - and thus his only option - to put up a shot, and consequently, that's what he ends up doing. A prime example of this was his back-door pass to Grant Hill in the last 5 seconds of the Spurs game. Clearly, Porter drew up the play with the first option being for Amare to catch the ball at the top of the key and look for Grant cutting to the basket. If that didn't materialize, then Amare was likely instructed to try to attack himself (or whatever Porter drew up... this part never had to happened and thus is kind of conjecture).
I think, no matter how much people want from the guy, "That's Amare". It's how his basketball mind works. The key might be to embrace the fact that Amare is first a brilliant scorer, that he can also be a great passer, and that he ISN'T a playmaker. Normally, that's okay for a big man, but more often than not, Amare catches the ball 13-17 feet away from the basket. His first inclination is to try to score. So, with his mind fixated on the rim, he either shoots a jumper, drives and dunks, takes one dribble and takes the pull-up finesse shot in the lane, or whatever.
Bottom line is, Amare isn't a shooting guard and is less effective driving from the top of the key and making split-second decisions on whether to shoot or pass. If I were Terry Porter, I'd try my darndest to get Amare into the positions where he doesn't have to make so many split second decisions - i.e. not give him the ball at the top of the key all the time and ask him to pretend to be J. Rich in mini-Dwight Howard's body, but I suppose we have to work with what we have. Porter has enough trouble speaking coherently that asking him to be the maestro of a complicated offense that opens up the floor enough for Steve Nash to be Steve Nash, allows Shaq to orchestrate the inside-out offense, AND puts Stoudemire in the positions to be an effective scorer/passer without having to add to that creating plays off of multiple dribbles is probably too much. D'Antoni did it decently (Amare averaged incredible numbers with Shaq last year), but we've all read about the supposed problems with Coach Mike's system.