I don't see why you'd trade the no.1 pick for anyone really :s (Exception being Durant Or Lebron)
Davis has potential, and a lot of years ahead of him. You don't throw it away and assume he wont be great. His ceiling is apparently to be better than Howard, not saying he will, but his potential is projected that he'll be great.
Gordon and Davis are young, let them grow together. Go through some experiences together. It makes perfect sense to just keep it going as it is.
Howard is not making it clear where he'll be after his contract is over, even if he's traded. If I was a franchise which isn't named the Nets, I wouldn't even bother gambling or destroying my roster(clearing cap space) for him. Nets have nothing to lose at this point, their franchise is already gone to hell with their stupid Gerald Wallace trade and pursuit of Howard.