M8 You don't know if it's underpowered or not. As I've told others the K1 (Shield Tablet) was able to produce Xbox 360/PS3 quality. The X1 (Pixel Tablet) was able to produce near Xbox One/PS4 quality--1tflop vs 1.2tflop & 1.8tflop--and the switch is using neither of them. The Switch is using a new custom Tegra, probably X2 or X3, based on the pascal architecture. It'll utilize a whole host of APIs including Nvidia's new NVN.
Stop assuming that because it's small it'll be weak. Processor and GPU manufacturers have been working hard to make things smaller, more efficient while maintaining and exceeding previous generation power. Do I expect the Switch to reach the Xbox Scorpio level of power, Scorpio being said to match the 980/1070 in Tflops, no I don't but Scorpio is also going to be sold for $600+ dollars while the switch is going to be $300/$350 at the most.
Also the switch is a console and a portable. I don't believe that Nintendo will keep the 3DS or Wii U for long after the switch comes out. I am all for unified systems. Being able to take the same games on the go that I play at home but without the latency and lag issues from streaming.