I was just at my local electronics shop here in Japan and noticed that Panasonic is now selling "All Metal" induction cooktops. Not sure about the details because the catalog is in Japanese, but the guy at the store said that they work not only with stainless steel and cast iron cookware, but also with aluminum and copper. The price at the shop was about $2500-$3000 for a 3-zone cooktop (two of them 3.0-kW elements) with a built-in broiler drawer. That's a lot less than I paid for my "primitive" induction cooktop 5 years ago :(
Does anybody have any idea how these new cooktops work? I wonder whether the copper and aluminum compatibility is achieved by simply adding a conventional heating element under the glass surface. Can copper and aluminum be heated by induction?