Who cares what his motives are? Everyone will watch this -- at least, everyone with a uterus.
Everybody and his brother thinks their Super Bowl ad is an event within an event. Every year, almost all of them are wrong. Super Bowl ads are mainly just overproduced comedy blackouts without much of a selling point. But a marriage proposal -- followed (somehow) by an answer -- is real drama, especially if the answer is "no." It's worth the money for the publicity alone, but just imagine the traffic to a properly designed website.
If I were a dating service, I'd be all over this. I would literally rethink my entire 2007 marketing program. But there are scads of other advertisers who would similarly benefit. They should do due dilgence on this guy and make sure he's not a fraud.
Then they should put him on the Super Bowl.