Wow, it looks like a great idea! I'll definitely keep an eye on it.
I also just discovered that descent is going to be offered as a WiiWare product. So my 6DOF fix will happen one way or another very soon
What I like about the look of this game is that it is doing something new/different, in that it sounds like you will actually be able to make your own tunnels / destroy your environment. That's an awesome twist!