End of VoIP on the PSP

Starting from 31st of march, it will be no more available the Go!Messenger service over the PSP; the cause?

"Although it proved a popular concept, achieving a significant number of registrations, it didn't gain the number of regular users that British Telecom and Sony Computer Entertainment Europe were aiming for."

Currently it seems that there isn't an alternative software to Go!Messenger, we wait for possible future progresses.