To the right of the fireplace I would love to see custom bookcases built to match the angle of the staircase.

If you have young children, I would leave the area that is open under the other part of the staircase and use it as a play area for the kids.
If there are no children in the house, you could build in a wine cooler if there is space in the other area, closing in the remaining area.
Carolyn Albert-Kincl, ASID

I would recommend enclosing the landing 'box' completely and cladding it in a accent material. This could serve to make it a piece of art. It will be difficult to make something functional out of that small space but I think you could still make a beautiful modern element out of it. Next to the fireplace could serve as an art display area with room for a console. I think the stairs will be so beautiful that you won't want to take away from that.

Use your imagination and make it work for you... it will come as construction moves forward.