I'm not sure it will ever be the answer to world hunger, but lab grown meat is still a very promising idea. It removes the moral question of whether or not eating meat is acceptable, so you could see a big drop in the number of vegetarians and vegans, thought obviously some do it for health reasons rather than moral.

I think another impact it would have is environmental. Raising livestock has a massive carbon footprint which could be eliminated so long as the energy source behind the lab grown meat is renewable. Nuclear powered meat factory? Sign me up!