It seems like it would be possible to have the stringer, with part of the cabinet blocked by it, and a couple of drawers simply being false fronts. And it seems like you could put a rail in without destroying the design.
I think it is a pretty cool idea, particularly in a place with limited space. I would probably use a slightly different design that didn't try to maximize all of the space (probably a more traditional looking cabinet with nice trim around it), but the concept is intriguing.
at our house the space under the steps (or at least the tallest part of it) is where we have our network and phone setup.