It should be the HDS!There is no excuse to not have at least 720p screen in 2017!Even,smarthpones of 150$ have a 720p screen!And ds lite succedeed by the dsi revision which had bigger resolution,samely the nintendo HDS will be succeed by a revision with bigger resolution,the Nintendo FHDS but knowing nintendo it could be just the Nintendo HDS+/plus! :P
Next nintendo handheld will be a collaboration with amd!That's a megaton!
Also,iwata's recent interview is very promising!He implied that nintendo won't sacrifice any advanced functions,characteristics etc,as nintendo has done with previous handheld/home consoles!