Uhm, DAD, Riftrunner is not going to have a 3d engine, it's still going to be the isometric engine of Divinity. The only difference is the characters are made of polygons instead of sprites.
And non-fixed NSEW, and zooming does not make an isometric engine into a 3d engine. There are isometric games, where you can zoom and rotate (A.D. 1602, e.g.), and they are still isometric and not 3d. Expert. (Now I've mocked you <img src="/ubbthreads/images/graemlins/badsmile2.gif" alt="" /> )