is it possible to change your minecraft username now with 1.6.2?

No but they are planning on adding the feature.

Nope, but when changing your username is possible it will definitely be posted here on MCF.

Nothing something I am looking forward to as a server owner.
Really hope they do this right and not screw us over without a conversion system in place.

I really hope they do, because i really want to change mine!

No, not yet. Maybe never.

Nope, no current way except with things that are not officially input' into the game already. Maybe in the future they will have the option, though.