Updated March 21, 2017: Effective today "the Wizards Account System is now the only account you’ll need when playing in live Magic events, accessing our website, play history, or any of our other non-Magic Online products that require an account." This transition is designed to provide a more seamless experience.
The release can be found here, complete with steps to take if you encounter issues. The system will be down until approximately noon Pacific Time to facilitate the update.
Today it was announced that there are changes coming to the way Wizards and Tournament Organizers communicate regarding events. What are those changes? We don't quite know! However during the system migration the ability for Tournament Organizers to look up DCI Numbers will be lost.
So what does that mean for you? If you know your DCI Number - don't worry! Wizards recommends syncing your DCI Number - required to play in sanctioned events - with your Wizards Account. If you have a number but cannot remember it, visit the same link and log in to recover your DCI Number. Wizards recommends completing this before March 21st. Players experiencing issues with the system can contact Customer Support.
The current event reporting software has long been maligned by tournament players. It is possible that this change means a more robust system is coming that can better handle the current size of tournaments.