Love the question, but I'm not sure about this strategic application. It forces an employee to disclose what might be very personal information or fudge, sharing something more generic and not really a passion at all. For instance, the person taking my order, listed "food" as her passion. From the looks of her, that was no surprise. Yet the answer had to be so short and potentially bland to fit on her name tag it really wasn't the conversation starter I am sure the person who came up with the idea expected it to be.
Here's a great application of the question though: Answer it for yourself, identifying your own passions. Then make sure you're: