You never know, EM waves might become obsolete for communication, but what are the chances, with the newrly limitless technologies that could be desined by other aliens, they those won't give off EM waves as a byproduct? I say pretty good. we might pick on their EM equivalent 'sonic booms'.

I think it is much more likely in fact that we will pick up alien presence from EM anomalies in outer space (I use anomalys in the most strict/conservative terms here) than by picking up on somehting as obvious as a communication signal. The problem is there are so many thing sin the universe taht seem anomalous, how do we seperate the natural form alien made?

-Jusitn Kelly