MCV is reporting that GREE will close down OpenFeint.
It's probably not going to be pretty since the service is being shut down on December 14, and apparently developers haven't been properly warned since they might face severe consequences.
In fact games that support OpenFeint might experience technical difficulties when the system shuts down.
This could be handled by a simple update, but the problem is that every app would've to be re-submitted to Apple and then cleared again which could take weeks.
According to GREE, the easiest solution for the developers is to incorporate GREE's own system before OpenFeint is shut down.
So, if you've got apps supported by OpenFeint, it might be worth keeping an eye on them during the next month or so.