The idea isn't bad, but it need to be based on the player id (to avoid x hundred entries from all the name changes, some players make each day).
I don't know if this is possible, but it would be great, if i can give a player an own nickname (which is shown for me everywhere instead of the real nickname from this player). If i set the nickname from jitspoe in my friend list to "BigBoss", it would show me "BigBoss" everywhere. The only problem is, that it would be more difficult to catch cheaters then (if everyone has another name for him). Maybe something like "[own nickname] real nickname" (example: [BigBoss] jitspoe) instead of replace the complete nickname would help.
If we have this, we could go a step higher and add an option to mark the player on the "friend list" as friend, neutral or foe and make the own nickname in a specific color (friend = green, neutral = white, foe = red).
That would be really nice, but like i said, i don't know if it is possible.