The real question in my mind is still compatibility with key technology which engines will be designed around. What would the significant differences be if two consoles are both more powerful and more efficient at the same time with current future rendering technology compared to a console which may not be compatible with some of the design choices. I just wonder if something like using tessellation might make it difficult to port models backwards to older hardware?
As I said in my previous post, the feature set of the Wii2/Café won't be far off from the ones of the PS4/X1080, therefore engines could be ported around more easily this time around. What couldn't be is of course the level of detail PS4/X1080 could afford.
Tessellation could very well be part of the Café GPU, a less advanced as what can be found in current DX11 GPUs is already in the RV7x0 silicon. And it's definitely a possibility that AMD includes a more recent version of their tessellation engine in the Café's GPU.
And in the worst case scenario where the GPU wouldn't support tessellation at all, it wouldn't be a deal breaker for ports. It would just mean less detailed models, but that would have already been the case given the supposed difference in sheer computational power and memory. In fact the PS4/X1080 games using tessellation would mean less work for the 3rd parties doing the port, they'd just go with the base models or lower tessellation level on the Café version (depending of the support of tessellation or not on Café's GPU).