I personally think username changes should be implemented, but they shouldn't be easily available (like obtainable with money, plenty of people have that). As for confusion, I don't understand why exactly that is such a big problem, since I would guess you would get used to it after a while, like a layout change. I don't think everybody is going to be flooding to get a name change either, so there really shouldn't be any ma-ss confusion.
I know there are several members here who were young when they first joined and weren't exactly smart picking names, and probably now regret the choice they made. The idea shouldn't be ignored completely, honestly.
Maybe there could be a username change thread done every two years for those interested? The two year wait is only to make sure the people changing their names are the ones that feel like they absolutely have to. Newbies probably wouldn't be able to change their names if they signed up at around the thread date and would have to wait until the next change.
But yeah anyway, I don't want to hijack this thread or whatever. I still support the basic idea of it though, but there needs to be some tweaks. :P