For all the ones that have a japanese PSN account can actually change their PSN Tag but they have a limit of changing it only 3 times. I'm not sure why but it sucks that japan gets this sweet deals while America gets the crappy ones.
But than again the Japanese make these consoles and games first and than get imported to other states. But yeah. Maybe one day we will get this update so no need to be hasty just be more patient. If you don't believe me than create a japanese PSN account.