I've finished "sculpting" the stalamites. Each is a 6" nail run through a 50mm base with successive layers of joint compound slathered on. Not really sure when I decided to use joint compound, but the results look (to me, at least) considerably more natural and believable than the styrofoam stalagmites I've made before.
The joint compound's considerably flakier, however, so I'm reinforcing everything with several coats of, again, watered-down wood glue. After enough of these, the outside will be extremely durable.
Once all of that's done (hopefully tonight) and dried (hopefully tomorrow AM), I'll start painting it. That should go pretty quickly: airbrush on the basecoat then a couple of layers of drybrush. Varnish that, then water effects and done.
I've stretched my non-existent photoshop skills to the limit to pull together a clever, attention-getting sign to place by my display board. I'm going to keep that close to my chest until the tournament, though: more because I keep dicking around with it than from any coyness.
Finally, I've loaded up most of the display case: my Daemons on one shelf and my Dark Angels spilling off of another. The top shelf's being saved for my Skaven (who are, understandably, a bit too busy psyching themselves up for the NoVA to spend time in the display case) and assorted one-off models that I've done.