No word yet on when it will be rescheduled for, but obviously we'll let you know as soon as we do. Until then, you can always console yourself by checking out what we expected to see at the event - namely, Android 4.2, the Nexus 10, and the Nexus 4.
[Update: Invites Open Again] WhatsApp Calling Goes Live For Everyone, Provided You Have A Recent App Version And Get "Invited" By Receiving A Call
[Update: Nexus Player] [Flash All The Things] Android 5.1 OTA Roundup For Nexus Devices
[Android 5.1 Feature Spotlight] Pattern Unlock Gets An Updated Animation