Is it literally a DJC or rather producing the effect of a DJC?
As much as DJC would probably improve his combo game, it is going to be hurting him a lot in other aspects. Like Silven said, his recovery is bad enough as it is, and DJC is going to hurt it even more.
I also liked the rising aerials, I wouldn't want to see them go. I always felt that if Ness did need a revamp that the rising aerials should be reworked rather a DJC.
Though if the DJC code still allows him to rise with an aerial if the player wants then that would be amazing, while not harming his already crap recovery and preserving what he can already do with rising aerials.
Edit:
You do realize that the new DJC would still allow rising aerials, right?
Anyone else want SWF to have some sort of realtime system of allowing you to view comments posted while you are typing your own comment?
Good to hear. In that case, I give my support for Ness having DJC

Just don't let the Lucas mains convince you to give it to him XD (Yoshi could be debatable but making Ness unique in that aspect would be great IMO)