Google started sending Google I/O 2016 to all who have applied for it. I must received the E-mail in the morning today.
If you haven't get it yet, than you don't need to worry. They sends these notices out in batches.
Registration time is 24 hours after you receive an invite. And just in case you don't get a golden ticket this time, here's what the email looks like:
Google also released App to vote for Android N Name Read More HERE