The video below shows a proof of concept of modular robots, capable to gather and operate as a group to create new forms and who knows whatever else. Take a look and don't mind the sound, they are not programed to kill yet (I guess).
It may not be so impressive, but the potential it has is enough to imagine that, with further development, this technology could change completely the way we build houses, bridges and everything else.
We can also imagine the technology being used to entertainment, sure, but we can't forget a war scenario, since these are robots and robots will (maybe) someday declare war on us. Imagine what a intelligent wall, able to move and reconfigure itself would do to attack and to defend.
Considering a longer development, it may be closer than we can think, the future when we will have robots like T-1000, which can go through iron bars, never smile and travel through time to kill people (ha!).
Until there, if you wanna know more about the project, just click here.