Let's try this again.
I'm planning on finally upgrading this site to the new code on February 16, 2013. This site will run in read only mode during the migration period (which should last a day) and after some testing (another day) I'll flip the switch and make the new site live.
If you haven't paid much attention to Danbooru 2, I've scaled back most of my more loftier ambitions and the new site is much closer to what we have now. You can kick the tires and give it a run at http://testbooru.donmai.us.
Updated