Actually I would say the future of microwaves is things like the miele dialog oven, which uses essentially MIMO techniques to direct the microwaves (at about 2.4 GHz IIRC, so the thing has a lot of shielding build in). I find it amazing how microwaves have just become worse over the last decades. Lots more functions in the UI without being needed, because the oven can't actually do anything interesting. AFAIK, pretty much every microwave still does PWM to change power for example.