I'm probably mistaken but - wasn't there a pre Jagger1,2,3 algo update that would have brought these changes into effect? In any case, the duplicate content filter's been here for a lot onger than that, and wouldn't that penalise sites duplicating DMOZ content?
The duplicate content filter is aimed (or was orginally) at exact duplicates - no one really knows how much needs to be changed before Google will no longer see it as "duplicate". It may be that they have fine-tuned this somewhat and that is part of what is impacting DMOZ clones but onlyt Google knows for sure. As for pre-Jagger updates, I personally believe that Google did begin targeting directories some time ago - not just DMOZ clones but including DMOZ clones - because they had become a source of PageRank distortion. That's a suspicion only, however - not something I can prove.
If you think your site has a hope, it won't hurt to submit it. Just don't sweat it if you never hear anything mjore about it.