As kitchens have become more and more the center of the home, the actual form of the room has changed, too. No longer is it a small, purely-utilitarian space tucked away out of sight. Often, the kitchen is now a place to gather, relax, and spend time. With that new use, we're seeing a lot of kitchens open up to vaulted ceilings as in these examples:
Vaulted ceilings really serve the main purpose of drawing in light (thus, people). It's not like they're for additional storage (okay, maybe a little, but most of it would be way too high!) or practicality (how do you clean way up there?). Do you think a heightened kitchen volume as seen here makes the room more of a public space in the home?