the specs are weird... an R700 GPU, which ran hot and was power hungry (very non-nintendo like). On the other hand the Wii consumed 18W at peak load. If Nintendo wanted to increase the power of their console but keep it relatively cool and keep power consumption low, they would try to find parts that kept heat down. In that case, newer chips on smaller processes would be a better choice (Trinity Fusion APU is at 32nm and has TDP between 65-100W).
However, Nintendo likes to customize the chips for their consoles. They tend to take an older design and tailor it to meet their needs. If work on the chipset of this successor started in 2008, it wouldn't be hard to imagine Nintendo using the R700 as the base for the GPU and then modifying it. but as i mentioned earlier, it doesn't fit Nintendo's design philosophy... then again, the 3DS has 3-5 hour battery life, so maybe that's changed.