In my opinion, you would be better off eliminating the 2 central recessed lights, and using a suspended or flush ceiling fixture. If your task lighting needs are covered by the under-cabinet lighting, then what you have missing is ambient lighting. Recessed cans tend to shed rather harsh down lighting. This will create unflattering shadows on people's faces. A glass enclosed fixture on the ceiling or suspended will give a softer more reflected light. This effect can also be assisted with a white or light colored ceiling. If your ceiling is high enough, consider an inverted bowl light. This will reflect quite a bit of light off the ceiling as well as give good direct ambient light.

Modernhouse, your remarks reinforce my feeling that where the lights are, they won't do much for task lighting and they aren't going to give even ambient lighting. The 50-year-old kitchen right now is about 9' X 10.5,' with all-white walls and cabinets and a light floor, so it reflects light well. We have most of the original light fixtures including a can light over the sink area and a 3-light semi flush opal-glass inverted bowl that has 3 CFL's in it now. There's also a small hood light and one small incandescent under-cabinet light, and taken together there is plenty of ambient and task light now, but the ambient is fairly glarey.

The kitchen gets daylight only from adjacent rooms, and with darker surroundings after the remodel, I think we probably will needc more light. Maybe keep a surface-mounted ceiling light in the center, as you suggest, and supplement with can lights to cut down on the glariness problem?

Another problem I just noticed is the under-cabinet light above the sink. The wiring will have to come from somewhere, because there won't be a ceiling or soffit to conceal it. (Cab itself was the GC's suggestion as we have limited storage room, even with moving a wall.) Also, the light itself will be visible through the window behind the sink to the sunroom on the other side, which is a few inches lower than the main floor. Should I just forget that particular light, plan on moving those two can lights closer to the countertop, and depend on the under-cabinet lighting on either side of the sink? (If the kitchen were larger, I'd forego the over-sink wall cab, but we think we need the extra storage.)
I probably will want some kind of light at least over the stairwell - maybe pulled back some to illuminate the pocket door area and the countertop on "Wall C."

More comments welcome... sure wish that refrigerator didnt stick out the way it does, but it doesn't work as well any place else.