There are plenty of improvements to be made regarding graphics, even for Nintendo's games, none of this "oh they're good enough now" nonsense, they wont be "good enough" until they reach CGI quality, which likely wont happen with their next console. I highly doubt they'll go with a console/portable hybrid, they'd be making much less profit from one console as opposed to two. Unless this console/handheld hybrid happens to be cheap and powerful enough to run around PS4/XB1 quality games in the future, and unless Nintendo can make as much profit with one as they can with both a console and handheld, it's not happening.