Not that I think Darko will be the answer to the knicks problems but this is a potentially smart move because:
1- If both players are in fact trash, a younger pile of trash will be more valuable than an older pile of trash with injury history (back problems)
2- A 7ft player is more valuable then a average sized SG, especially if again, both are piles of trash anyway
3- Darkp actually does have potential to be anywhere from decent to pretty good, especially in this system. In his final season with the orlando magic, he played the most games of his career, avergaed career minutes along with damn decent stats:
http://www.realgm.com/src_playerfile/830/darko_milicic/ Orlando does have a system that is similar to ours and remember, Darko was also playing next to Dwight Howard putting up decent stats. Again, not saying Darko is guaranteed to help us but he is potentially way more useful then q rich anyway so why not make the move if it doesn't hurt the overall plan. The knicks have had no inside presence for years and this guy could be someone that fits very well in a D'antoni system. And if not, he is just a 1 year rental that will be more valuable to us in a trade than q rich simpply because of his size alone.