The procrastinators out there have missed their chance to (maybe) give Google $900 for a ticket to Google I/O this year. The registration window is closed, but we don't yet know who's going. That news will hit this coming Monday.
The morning of April 21st, Google expects to alert the winners of I/O slots via email. At that time, they will pay up the registration fee and all will be well. Even if you don't win a spot in the (supposedly) random drawing, Google will still send you an email to confirm that you did not win. So, don't get too excited when you spot that I/O email Monday morning.
Google I/O is happening on June 25-26th this year with a greater focus on design. As usual, we expect Google will hand out some fabulous freebies at the show. Maybe some Android Wear devices? We can only hope.