>>2
Well, honestly, I don't think there's a problem if there aren't a large number of contributors. As long as people know the sites exist, and there are a few dedicated people that already run around all the different imageboards / random art sites for a specific thing they really like anyway, it'd really be more archiving. If the danbooru discussion system was worked on a bit (or has it been?) it could become more like a regular board for the really, really popular stuff, though... maybe.
Not sure how much I like that, though.

In the end, perhaps an aim could be just using danbooru as an image gallery page. But when you're that focused already, is tagged searching really all that useful?

And yeah, sagubooru is absolutely horrible.