I just though I'd ask.
Here's what I'm fairly sure about:
1. Fully backwards compatible with the Wii and Wii U. Gamecube games will be in the eShop
2. support for four gamepads. Gamepad will probably be higher resolution (720p most likely)
3. 3D support, but only if 3D TVs actually kick off in time for Nintendo to implement 3D. Otherwise no 3D
4. most likely no 4k support. The Xbox One and PS4 don't support 4k games, so Nintendo won't bother implementing it
5. Clearly more powerful than the PS4 and Xbox One, but won't be more powerful than the PS5 and Xbox Two
6. Will problably come with a virtual reality headset, like a refined Oculus Rift. otherwise Nintendo will have to find a different edge.
7. Either will come with 128-512GB NAND and/or 500gb+ HDD, or will have a means of upgrading storage (either internal hard drive support or a possibly proprietary flash module)
What about you? what expectations do you have from Nintendo for their future consoles?