Still working on mega project builds. This one is going into my own PVP server which (will) contain 4 theme'd biomes inside of a 155m sphere - inside of a 255 meter containment sphere inside a 1000m+ void. The outer sphere acts as both artificial sunlight and a drop-death height of 50m. 4 more outer panels to go (water and lava) and it's ready for interior work and redstone - including command-block powered proximity traps that don't have any triggers marking them as well as hidden walls that will 'unzip' when you find them. These along with many many features I've come up w/while doing this block-by-block - no worldedit. This build started late October 2013. It's probably going to top-out at 1 million blocks in all.
There's also this earlier teaser when the framework and 2 outer (lava) panels were completed 6 months ago :
I'll post more milestone videos and an announcement when the PVP server is configured and up-and-running.
Also here's a screenshot of the latest progress :