Hopefully the new editor will be available sometime in the near future. Thomas mentioned to me the other day about there being a beta test sometime over the coming weeks, but didn't say whether it would be private or public - he didn't have much time to talk.
The new IDE as far as I can tell looks a little like the godot engine you've shown in that youtube video (style wise in both color & the blocks on the edges). The whole point in the new editor is to make it more workflow efficient & more flexible, plus... no more bloody wxWidgets, so with any luck it will be completely - or in the very least almost completely - bug free.

Aye, the devs don't really like to share their development stuff publicly, as the list of feature requests & what they are doing is constantly expanding (requests from you lot, requests from me & Thomas & Daedalic, etc). All in all it's keeping Simon really busy!