As you probably know Wade Arnold took the place of Patrick some time ago as project leader but no real big changes were committed since then.
But after the partnership between Zend and Adobe things started to change and amfphp started to move forward to the Zend Framework… and in fact many developers were afraid about the real future of amfphp.
Bt, as Wade said, the amfphp core will remain separated from the framework implementation ( a framework which I will never use however ), in order to have a shared core and 2 different branches for the implementation. ( a new release was promised before Adobe MAX )
However I’m afraid too about what could happen expecially when 2 major software houses “promote” an opensource project. Probably I’m too sceptical, but I believe that in the future more and more things will be only supported in the zend_amf and not in the standalone amfphp project.