Ubuntu's Python maintainer Barry Warsaw recently announced their goal to have no Python 2 in the "main" part of the repositories by their April 2014 release: http://lwn.net/Articles/469939/
I think that's probably a too aggressive schedule to actually keep, but here's hoping.
For someone just starting out with python (on linux anyways) that means they are probably going to fire up that interpreter first.
I was wondering myself actually if any of the distros would switch to 3.0. I think a lot of packages would break if that were to happen.
As you've said, Arch has already switched but their package release isn't really typical for most distros.