SharePoint SP2 will expire 180 after implementation of the service pack.

Taken from the SharePoint team blog ....

"During the installation of SP2, a product expiration date is improperly activated. This means SharePoint will expire as though it was a trial installation 180 days after SP2 is deployed. The activation of the expiration date will not affect the normal function of SharePoint up until the expiration date passes. Furthermore, product expiration 180 days after SP2 installation will not affect customer’s data, configuration or application code but will render SharePoint inaccessible for end-users"

A KB article has been released on this and a fix is being worked on quickly!

We all make mistakes ...