Get more fridge/ freezer space then you think you need. Wish we would have ponied up for large fridge and freezer during our project last year. At the time, the Maytag seemed plenty big, plus it was only a couple years old. It seemed silly to drop a few thousand $. But we now are constantly short on freezer space, and often need more refrigeration space (leading up to dinners, etc.). Will probably wind up w/ installing a fridge/ freezer in the basement to get more space.
More then 1 sink is great, and make one as friggin' big as you can fit into the space. And go single basin only -- no two or three compartments, as it makes it tough to wash bigger pots and pans, etc. A high faucet is helpful as well.
Run more electrical circuits then your electrician says you need, so you can use various applicances, etc. without danger of popping circuit breakers. And put in a ton of ceiling lights! Hanging a couple pendants over an island does not make for proper working light. We consulted a real lighting designer and wound up with 3x the amount of fixtures the architect put on the plans. Oh, and undercabinet lights can help if you will be prepping below wall cabinets.