I am going to change my username. Definitely. I'm going to change it to my first name and possibly the first 3 letters of my last name. Just for simplicity.
Hm. I'd honestly advice you to stay away from implementing both your first and last name in your username. It takes away a bit of privacy.
One of my biggest regrets is not snatching up the name BlackKnight when name changes came out. I was too hesitant, and by the time I had decided to change it, the name was gone, as were all logical variations of it.
So by this I understand that when name changing came out a paid account named BlackKnight didn't exist yet?
I might change mine, but only to get rid of the numbers. I would still keep "Kalia" as the beginning, which everyone knows me as, and if that name is taken, add something simple to the end of it that would make it my own but easier to remember than a series of numbers (that I picked because they are my birth date, but that doesn't help anyone else remember them ).