Personally, I never mind seeing additional screenshots of the same dungeon. It may not be the most exciting thing, but it's still something to help tide us over in the meantime and can lead to some interesting discussions and speculation. As for the concept art, that stuff blows me away each time they release some new images, but I can see why they'd want to spread it out over time. Looking forward to those bestiary updates as well.
"I doubt I said "every Thursday there will be an update". Regardless though, we have some bestiary updates planned to show up "soon". Weekly updates are tough because while we have a ton of concept art we could probably easily run through all of it before the game's release, and frankly, I'm not sure how many more screenshots you guys want to see of the same dungeon. We're just not to a point where other locations are polished enough to show. We'll get there."
For those of you wanting more updates on the game, it's obvious that they're just not ready to show the other areas yet. I'm sure once they're polished enough (aka: filled with enough unicorns), we'll be treated to all kinds of new media from the game.