Pillowfort's approach to this was to make a reblog not a copy, but just a window to the original. If a creator deletes the post, it takes all the reblogs with it. It also means all comments get collected on that single post, its setting for privacy and whether comments are allowed obtains everywhere, etc. It also means that someone could post something innocuous and then later edit it to have some kind of horrible gore picture in it, and all the reblogs would propagate that change. I find that rather alarming but I guess they want to let abuse reports handle that should it happen.

I am also in the camp that wouldn't want to see reblogs on Dreamwidth. I wasn't a fan of Livejournal's interpretation of the idea, either.