Honestly I wouldn't do that trade. I mean, Duncan was last year's MVP, and Amare may never be an MVP in this league at all, but there are a number of reasons I'd keep Amare over Timmy D.
First, it's the excitement factor. Obviously, if Tim duncan brings W's, then that's exciting, but by I'd say that on the old excitement list, watching Duncan play, grass grow and paint dry are right there near the bottom together. Now, I appreciate other parts of the game other than "slam dunks" but Stoudemire doesn't just dunk the ball. What he does is a whole new thing.
Second, it's just the personel we have on the team. Amare and Marbury works. Duncan and Marbury really doesn't. They might play well together, but Steph and Amare have the chance to be something special together. Steph and Duncan isn't like the odd couple with oscar and felix, it's more like oscar and.. well, steph..
Lastly is sheer talent that Amare has. He may not be Tim Duncan caliber yet, but he's a once in 20 years kind of guy. He's the most powerful player to be drafted since Shaquille O'neal, and as far as big men go, he's one of the quickest too. I'd love to see Amare have a jumper, but the fact that he doesn't almost makes me like him more. It's funny, Tim Duncan has 20 moves downlow, so you really don't know what he's going to do. That's how he scores. Amare has 2 moves. Either he goes right all the way, or he takes one dribble right and spins left towards the basket. Even still, nobody can stop him straight up. The guy averages 13.5 points, 9 boards this year. Imagine him 3 years from now! And you would trade him for Tim "don't fall asleep there's a game going on" duncan? Please!