The living rooms, family rooms, master bedrooms all have the same sophisticated surround sound, high quality large LED screens, etc. It's harder now to justify the space and expense of a dedicated theater. I like the idea of a VR-room. Maybe multi-directional moving floor, padded walls, wind simulation, surround sound etc... Now that would make for an interesting home talking point.
As far as kitchens go, the trend I see is this: "Showroom kitchen" with large eat-in breakfast area and family room in one. An auxiliary kitchen connected to this either thru service doors or connected by dumbwaiter in the basement. So people can hang in the kitchen, eat appetizers, open the fridge, open a bottle of wine, etc.. while the heavy cooking prep is done in the service kitchen.
The idea about an "appliance garage"... I don't know... No one is hunting around looking for some appliance they use once in a blue moon. People are always going to have counter-top coffee machines, etc, just sitting on the counters.
As far as master-suites go... The advent of the internet is making people more creative and specific about what they want. What I'm building are really that, suites, like what you would experience in a high-end hotel. Double door entrance with a small anti-foyer, a small study room/area, double door entrances to the master bath and master closets. Sometimes the baths are split into his and her, as well as the closets. The big addition I've been doing lately are adding small, concealed bar areas. Mini-fridge, sink, coffee-maker... who wouldn't want that? Wake up on the weekend, have a steam and a shower, make a cup of coffee and sit out on a private balcony before ever leaving your room.