I think that will depend on how well the WotC VTT does. If they have a smooth and attractive GUI and an engine that automates the rules correctly, plus if they build in good onboarding tutorials that lead you through the rules as it teaches you the system, it will make D&D attractive to an even wider audience, decrease the learning curve, and--if they add a find-a-game feature--create the biggest venue for finding other D&D players that exists.
If it is just another set of books, then I think it will do fine, but I can't see it creating another lightning in a bottle moment.