I am by no means a business major.....
I feel there are a few basic and key questions to be asked....
1) What age group are you targeting?
In my plan? Four distinct demographic tiers get varying levels of support starting with tweens, who get a very accessible implementation of D&D similar to the red box concept, but without the dead end aspects of prior intro sets. Extensions of this set follow gamers through high school, and comprehensive game presentations work through university level. After that, we provide a self-support framework for all editions through free/semi-free stuff in the social network, perhaps similar to GW's Specialist Games.
2) What level of cross marketing are you willing to do? (toys, movies, books).
For D&D as a thing? Next to nothing. D&D is a big brand in RPGs and a terrible brand everywhere else. D&D is meaningless; its essential attributes can be copied by anyone and if anything, will grow more popular for not being D&D. As a brand, D&D sucks.
But Dragonlance has some gas.
So does the Realms
So do other worlds.
But D&D? Outside of an RPG who cares? Hell, even as an RPG, who cares? You can steal any set of D&D rules and call it Finding Swords and Path of Wizardry and people will adopt it. You can rip off core D&D elements and use them to create a dozen MMOs that will be more popular that D&D Online.
D&D *could* be a brand in the way Marvel is a brand: a mark for a house of creative traditions and a distinct evolution in style that creates cool stuff by exploring them in RPGs.
Unfortunately, this would require creative folks making fluffy, stylish stuff. WotC has innovative mechanics designers, but no talent for anything that would make D&D broadly interesting.