After many user and institutional requests, we are extending the Academic Login activation period for a month for all ~okeanos alpha users. That is from August 11, 2013 to September 11, 2013.
It seems that as of today, almost every Greek Academic and Research Institution has enabled support for ~okeanos, so all alpha users should be able to enable the new Academic Login method on their Profile page.
So, if you want to guarantee your transition to beta, please proceed with enabling Academic Login, now.
the ~okeanos team