I think that people are forgetting that New York has traded some 1st Round picks already. In the McGrady trade, they dealt Houston a possible swap of 2011 and the 2012 pick itself.
Knowing that picks in consecutive years can't be traded, New York can't trade a pick until 2014.
So 2 picks would be 2014 and 2016.
5 picks would be 2014, 2016, 2018, 2020, 2022.
Good luck selling Denver fans on not getting your full return on your best player until 2022. Also good luck in getting the Knicks to trade their first round pick 12 years from now.
Carmelo will not be traded for expirings, since he is one, or garbage. Denver would rather let him leave, decline Chauncey's option, let K-Mart leave, and rebuild around Ty Lawson, Nene, and a ton of cap room.