Sometimes I like to change my name to include a message. For example, if I suddenly have to go out of town for work, it's nice to change my name to "Thad (gone until tomorrow)" so that people know when I'll be back. I know I can change my profile, but it's nice to put it right into my name so that others see it right on their games page. If I had to reserve names ahead of time, I couldn't change my name last minute. A names history (sorta like eBay does) would probably be best.