It looks like everybody is talking about this, so here are my 2 cents. I remember my NM process still very well (I became DD few months ago) and I know very well how painful is to ask somebody to upload packages for you again and again.
On the other side the NM process definitely helped me to produce better packages and I learned some new things. Debian currently has pretty good quality and having such entry barrier helps to this. And I do not thing that the barrier is too high.
Maybe I was just lucky, but NM process was not that long and complicated as I heard before than I actually applied. The only thing that took incredibly long was just delay between DAM approval and actual account creation, but AFAIR it was only because responsible people were busy with release. Otherwise I'd go through NM in 3 months and I feel this is perfectly acceptable time for this and there is no need to split it up by introducing some intermediate level.