No, it’s not possible to change your nickname in Quake Live. The only thing you can change about your nickname is the following:
- Your clan tag (5 characters maximum, use the command /clan in the Quake Live console)
- Capital letters or lowercase letters
However, what you can do to get a new nickname is create a new account in Quake Live, once you have a BETA key. To create a new account just log out of quake live. Log back into the beta screen and register a new account on the screen where it also asks for your email.
Id software does not care too much about duplicate accounts. Quake live does not exclusively use the number of registered accounts as a reference for traffic and popularity. The userbase statistics would be very inaccurate which would not convince potential advertisers. Don’t spam too many new accounts either though, just as a precaution.
It’s also been said that once quake live is publicly released and is out of the beta, all stats and accounts will be deleted or reset. Then it could be possible to get an account nickname which has currently been taken already. Though it’s not entirely sure this will happen.
Read these Quake Live config customization tips for many more useful console commands.