phaedruss on 09 July 2014
http://www.nvidia.com/object/tegra-k1-processor.html
http://en.wikipedia.org/wiki/Tegra#Tegra_K1
Those are the specs for the tegra k1. It's highly possible to have a handheld more powerful than the wii u but I'm not sure how expensive it is at this point.
Another thing, I recall that Nintendo said that the Wii U would be the first or the example for this unified architecture. I'm not sure if that means the same line of chips, i.e. PPC cpu etc. or if that means similar memory architecture, or simply that the next systems will be fully backwards compatible with the wii u but not necessarily 3ds.
