Well, it is serious. 90% percent of the world's plants rely on pollination, and bees are one of the major pollinators. If they were to go extinct, we would lose a lot of the worlds' plants and we would start dying off as well.

Now many people say that we can still survive without bees. Yes, it's possible. The most probable outcome would be that after they would be gone (and all the traveling bee vendors and bee raisers had no more bees as well), there would be a world recession much like the one we're coming out of today caused by the fruit industry failing. Everyone else would then have to make up for the bees' job: start pollinating themselves. In one of the Asian countries, I think it was Thailand, I read that the Yeoman farmers have to pollinate their own crop (running around with baskets and climbing trees) as the bee population has gone extinct in their own country and they can't afford bee imports. This would be just one of the many ways the human race can go to the cleaners if this issue is not watched.