Neogaf user kirbasin has uncovered some references within the release notes for the upcoming Unreal Engine 4.14 that may hint at imminent plans for name changing ability on PSN. Several references are made to an “Sce Np Account Id” being used in replacement of “Sce Np Online Id.” In simplest terms, this may mean that on the back end of PSN, Sony has made changes to accommodate both an account ID and a display ID. This kind of a setup would, in theory, allow for an account ID to remain permanent, while the display ID would be what everybody sees publicly. This would be the same way Steam handles name changes.
The inability to change PSN names has long been a point of frustration among users, as it is something that has been available on Xbox for many years now. The first name change is free on Xbox Live, and any additional future changes cost $10 each.