If you wish to have granite or marble as island top, do ensure that you have invest in a much more studier base that is capable of support the heavy weight of these material. The granite top can have box shape cuts at certain areas to include a sink, a grill and an electric stove. Below the island top one can add pipes to supply water to the sink or electricity to the appliances. The shelves can be polished or painted differently from the top to get a splendid looking kitchen isle.
For those remodeling and looking for an "open" feel where perhaps the wall or half wall separating the kitchen and the dining room is taken down, a strategically placed island acts as a subtle room divider mentally separating the kitchen from the dining room but with a much more open feel.
The drop leaves can be attached to the periphery of the isle top and they can be attached with hinges so that they can be folded along the sides of the isle. The bottom part of the wooden island can be a sturdy stationary base or have wheels included in them to make it mobile. The shelves of the wooden island can be of a simple type where they open up to compartments that store utensils and cans. Above the shelves can be a chest of drawers that are used to store cutlery. The island top can be of a sturdy wooden base that is polished to make it look like a dining table.
For example, we have seen islands of concrete when the rest of the kitchen countertop is made of granite or another material. We have seen a black island used as a nice "dividing wall" to keep the kids away from a white kitchen.