Some oven, can't remember which company, had a nice feature where the oven rack was designed more like a drawer slide than just a sliding rack. Seemed to be safer for larger pans.

Refridgerators that have motorized shelves make accomodating different height containers a lot more convenient, but I guess it's just another motor that may break.

The Sharp "drawer" microwave ovens seem like a good idea. The micro can be installed below the countertop and loaded from the top like a cabinet drawer.