So yeah, here is how it's gonna happen.
Once a year, you will get to change your name if you've gotten bored of it, or just feel like a change. On February 8, you can go to your profile page, and where it usually says your username (go on, check now if you don't know what I mean) it will have a text box with your name in it that you can click on and change.
But it's only on February 8. Any other day you will not be able to change it.The other thing is that the "Username Changes" topic is be back (
link here) so that everyone will still know it's you after you change your name. Just post in that topic if you change your username - you don't need make a new topic. If everybody's change is in one topic it will be easier to find.