I heard during the beta that there were plans to restore the old Distortion node in the Material Editor that we had in UE3, which I frankly would welcome with open arms. As cool as refraction is, it’s not a suitable replacement for everything we used to be able to do with Distortion and is significantly harder to use to get the results you want.
Is there any word on when this may be back? I’m itching to port some of my old stuff right now! (I would post on AnswerHub but it everything I write there quickly gets buried).