I don't think the Wii2 will use IR anymore, it will probably use gyros like in wii motion plus. That mockup also looks fairly uncomfortable, either the handles will be too short to serve as a wii remote or too long to be easy to handle as a traditional controller. Also, when separated the D pad and second trigger will become essentially inaccessible, resulting in the wii remote portion not having any usable direction control.
I personally expect the wii2 remote to be fairly similar, but using gyros to eliminate the need for the IR pointer (if they can avoid the need for constant calibration). They may keep the IR pointer for backwards compatibility, though (this shouldn't be necessary, if they use a dual-core system they could put an emulation layer in there, but that may be more work than Nintendo is willing to do). It may have a microphone, and will likely have a lot more memory (probably similar to the Wii now). I doubt it would have a screen, but if it did it would probably be a small, low-res, color, screen without touch capability. And I expect something like the Nyko controller's ability for addons to duplicate button presses on the remote. There is also a change they may replace the D-pad with something like the 3Ds nub. They may also add another two small buttons next to the A button, perhaps just duplicates of the 1+2 buttons. Another possibility is a slider either on the side or around the A button for adjusting 3D depth, similar to the 3DS, or some sort of spinner which can also have its four direction pressed.
I expect the nunchuck to also remain mostly the same, perhaps with two buttons near the joystick, but remain wired. I doubt it would get gyros, but it might.
I would hope they will release something like the classic controller pro with accelerometers and its own dedicated bluetooth connection. I doubt the design would change too much from that.