There's been a lot of talk online about next gen consoles being underpowered. Why would anyone pay $400 plus for a console that's only a little improvement over this gen?
A little improvement? Even the lower end rumours have been around 10x the real world power of the current generation. That's as big a jump as was seen this generation over the previous.
If you're wanting a theoretical HD 8870 in there then your really asking for more like 20x the real world performance and that would equate to one of the biggest generational performance leaps ever (possibly the biggest).