The Arts & Industries Building is my favorite building on the Mall. I love its flamboyant Victorian colors, and I've been sorry to see it empty for so long. I understand closing the building, as it was unsafe, but I've been hoping for quite a while that money could be found to repair it and open it to the public again. I've often walked past it and seen a sign indicating that it was under construction, but never saw any evidence of said construction.
Now, it is covered in scaffolding, and a tower crane is visible behind the building. See this article for more information: http://www.grunley.com/news/projects/a&i.asp. We've got another 21 months before construction is complete, and now I can only hope someone's working on what to put in the building when it's ready.