i agree with tino, i have the 18mm and it's actually pretty great unless you're looking to shoot critical landscapes wide open for some reason. i also love the size, especially on an X-E1 makes for a great reportage or street camera.
you probably don't
need it if you're getting the 18-55, though; the 14 could be a better bet in that case. but there is something to be said for a fast compact 28mm equivalent with a proper aperture ring on a small body; it's like having a ricoh GR or coolpix A with better controls and a viewfinder. i took
all but two of the shots in this tokyo motor show photo essay with the 18mm not the best environment in the world to take pictures in but the 18mm made it more comfortable than it otherwise might have been.
otherwise i have the 35 1.4, which is phenomenal and essential, and the 60 2.4 macro, which is super sharp but an AF nightmare (presumably much improved on the X-E2). my next will probably be the 23mm.