Li Shenron
Legend
Complexity and faithfulness to D&D tradition are probably my only 2 dealbreakers about the next edition.
If low-complexity, rules-light is not supported, I can never play this game because my players won't even look at it.
Only millions of people who could be playing D&D but are not.
The complexity entry barrier of the game is still THE mean reason why I can't get most of my friends to even try this game. The all say "wow, looks like a totally fun idea, it's like creating a movie/book story together!" when I talk about it, but they totally hate the idea that you have to "study" the rules before you start.
WotC can choose the business strategy they want. A high complexity game means WotC customers will be only a few hardcore gamers, each of which will probably spend a lot of money. A low complexity game will open up the market to many, many more potential customers, which on the other hand will probably buy only the PHB. They can make their estimation and go with the first, if they think it's more profitable, but then they can't seriously come back weeping that "people prefer playing dumb console games" instead of D&D.
If low-complexity, rules-light is not supported, I can never play this game because my players won't even look at it.
I don't think there's that many fans of simple rules anymore.
Only millions of people who could be playing D&D but are not.

WotC can choose the business strategy they want. A high complexity game means WotC customers will be only a few hardcore gamers, each of which will probably spend a lot of money. A low complexity game will open up the market to many, many more potential customers, which on the other hand will probably buy only the PHB. They can make their estimation and go with the first, if they think it's more profitable, but then they can't seriously come back weeping that "people prefer playing dumb console games" instead of D&D.