There may be some problems with this idea.
First, those who are out noding all the chapters of Moby Dick or whatever whould have no more motiviation to do so, if each hidden w/u gives 0 XP, or will cram the "new Writeups" box. I'd like to node all 10 family recipes, but I don't want some pissed off user downvoting me, so I hide them, but I do want some XP.
Second, if I wrote a node saying "White people suck", and it can't be voted upon, it's an advantage to the trolls.
Other than that, it would be a good idea. I'd like to un-hide a w/u, not have nuke requests bounce my XP up and down, and the general idea is pretty good.