We usually don't allow username changes as it just goes against the whole sense of community - afterall, we all know each other on here by our usernames. However, I do make exceptions if you provide me with a new username.
Nanosani, that's the exact reasons why I don't condone username changes. We're a community - and we know each other only by our usernames. If everyone went and constantly changed usernames, the community would fall apart.