Just exactly as you said towards the end of your post,"I've thought of the built-in ceiling "cans", electrical outlet in the floor/carpet, and sliding track lighting." They are all options for an open concept room. Your electrician should be of some help along with your builder, and if you have a designer. We have an open concept home and have lighting at the entry, ceiling fan/light in the living room, chandelier over dining room table and pendant lights over the peninsula in the kitchen. It all works for light and we almost put in outlets in the floor but decided against it because of our beautiful hardwood floors. I think we could have put a can light around or above the fireplace area but we are happy with the way it turned out.
Good Luck!

Thanks for your reply, twotogo. I'm wondering which of the lighting options mentioned were best (or poor)choices to other recent homebuilders. I appreciate your comment that flooring outlets would mar your beautiful flooring. I'm glad you are happy with your lighting.