Ausiello is reporting that the season ends with more of a climax than a cliffhanger, which is probably wise since a The Event season 2 remains a long shot. At least the show is going out with a bang:
The episode concludes with “something that is truly momentous and, I believe, never seen before” on TV.
Not much we should get more spoilers in the coming weeks.
The Event Season Finale Will “Complete the Story of the First Season”