With a delay in Japan, one can assume that the new firmware update will be delayed worldwide. Those anticipating free PSP-to-PSP calls will have to wait just a little longer, it seems. However, maybe we'll be surprised by a firmware release that comes out in the rest of the world. Considering that has never happened, we won't hold our breath.
[Update via Kotaku: This announcement "will make no difference to the European and USA launch, which will coincide with the end of January firmware upgrade." Thanks, Espiox!]