Well ... unreal wasnt in two aether ... they just haven't had an alpha out.
There is a lot of work still and i think that only environment stuff (clouds and lighting, biomes n stuff) will still be going out progressively during next so 3 years (still, my own estimate if i look back the time im following them, no idea if Cameny plans something really special in the time). Than there is probably a ton of work for the overall capabilities of the engine, + testing it all properly. Its not a homework such a thing, doe it already has a lot of functional stuff for vehicle creation. I wont bury it no matter what people think.
Also, its not a SINGLE game engine ... its an engine for many stuff ... and whyte some great potential.