Please, I'm not sure the Nuggets even have draft picks to trade. For whatever reason, the Nuggets hate draft picks... except second round draft picks. They love those. I know of one first rounder they have, and it's the Bobcats future first rounder -- which the Nuggets traded this years (or last years, I don't remember) first round pick to get. When the year of that draft pick finally rolls around, they'll probably trade it.
But the Nuggets have the same issues I'm sure the Celtics have -- very top heavy in regards to contracts. Anyone with a contract that another team may think is worth acquiring is too valuable to the team. It's frustrating, the Nuggets are one of the 5 or 6 best teams in the NBA right now, but I think they need another piece to be a legit contender, and they don't have the means to acquire it -- and they have a lot of young talent, but they don't have the draft picks to acquire young talent to go with it to ensure a future as bright as, say, Portland's appears to be.
edit: Also frustrating, and completely unrelated, 'Melo still gets no respect. This year's literally, like, the fourth time he's been snubbed for the All-Star game.