Is the difference in the latter case just that someone clicks "ok, post this"? I don't think that a quality-review (or lesser, a mechanism to queue and release content to the site slowly over time) turns user-generated-content into site-generated-content.
If Youtube did a quality review, it would still be UGC.
If Youtube did a post-facto quality review (to remove copyrighted music), it would still be UGC. ...
Not honoring takedown requests is a different matter, and just sounds like a dumb call.
http://en.wikipedia.org/wiki/Section_230_of_the_Communicatio...
Also, I'm not sure why a quality-review process would lessen culpability if all the illegal stuff gets through anyway.
There would have to be the most enormous chasm, because the latter includes every publication that uses the work of freelancers, which is pretty much every newspaper and magazine, and their online equivalents, everywhere.
(Standard IANAL caveats apply of course. I think I have a reasonably good layman's understanding of this stuff since my work touches on this stuff, but you should talk to your lawyer if you want concrete advice.)