SuperNova on 28 November 2015
I can't really see Nintendo making a wiiU slim for all the reasons mentioned in OP and the fact that it looks positively tiny already next to my PS3 super slim.
I don't think microsoft is going to bother with a revision either, so that leaves Sony. That said, I think a ps4 slim is quite likely, especially if we get a die shrink. Although like others said, a hardware redesign is more about sales than actual formfactor. Sometimes a remodel is significantly cheaper to produce though, so that could come into play at some point.
