Two thoughts came to mind when I read this. (1) maybe there aren't any ground-breaking ideas to come up with. Perhaps the technology is at a plateau and the only changes to expect are permutations and combinations (e.g. mirrorless). (2) coming to a conclusion like this based on rumors alone is somewhat premature.
Well, Canon is the only manufacturer seemingly unable to put out a better sensor. Sony started it with the Exmor, but now Nikon (as in, Nikon-made sensors, not Sony ones in Nikon bodies), Fuji, Samsung, Leica and others all have sensors that far outstrip Canon at low ISO while equalling it at high ISO.
It's not that sensor technology has plateaued. It's just that Canon, almost uniquely among manufacturers, is unable to release one that performs much better than what they were producing 7 years ago when the 1Ds3 came out.