Yesterday, a bunch of YouTube users seemed to discover that the 'Partner Settings' tab was appearing in their account settings. The upload page said that videos over 15 minutes were possible. Some users even saw the message implying that they could enable revenue sharing for all videos. Did everyone become a Partner? Not quite...
This still isn't available to everyone, though. And YouTube enabling this feature seems to have caused both confusion and problems. Certain Partner related links were appearing on some account pages. Also, nearly all YouTube users who's accounts are not linked to a Google account were unable to log in (at least, I'm guessing there's a connection somewhere).
Is there more to this change than there seems to be? At the moment, no. Though if there are any other changes, someone is sure to find out eventually.