Marc Graboff is the man. He's the president of NBC West Coast and Universal Media Studios, and from my research, he is the person who can decide whether or not we see The Event return as a movie or mini-series.
His Twitter is @mgraboff, and based on the pattern I see for NBC Universal email addresses, his email address should be: Marc.Graboff@nbcuni.com. If you want The Event back, send him an email, and do it TODAY. We can't waste anymore time.
Remember, be courteous. Be respectful. Be polite. Ask nicely, but be enthusiastic. Speak from the heart. Tell him why he should bring The Event back.