Well, there are a few things...
1) Bobboau is mostly working on Ferrium now... I haven't seen him work on SCP stuff in a while.
2) He said previously that this build was more of an experiment than anything else; it would require quite a lot of work to clean up the code enough to be able to merge it.
3) He has a nasty habit of partially coding a buggy implementation of a cool feature, and then taking ages to actually finish it and debug it.
In short, don't hold your breath; I don't think it's going to happen anytime soon. I wish he wouldn't get people's hopes up with half-completed features.