I agree, I think there is a lot riding on this edition as well. If it doesn't do well and make a lot of money, I wouldn't be surprised to see D&D disappear as a supported classic tabletop role playing game - Hasbro will still trade (sit on) on the IP for board games, miniature games and computer games but I'm worried that if the community doesn't get behind this game in numbers i.e. buys into it with cash, it won't be there in the future for the next generation of roleplayers.
Of course, we'll be o.k. because we'll just keep playing edition X of the game but it won't be good for the long term survival of the game as a mainstream tabletop rpg...