The problem I've seen with the D&D brand is how to effectively monetize whatever level of name recognition there might be. There hasn't been any major new authors or characters in the novel line since they picked it up; it's still mostly Drizzt, Salvatore, Greenwood, and other stalwarts from pre WotC days that have stuck around. While this isn't necessarily bad, it's not necessarily good for the long term growth and viability; the line will need new blood at some point to sustain itself if they want the larger brand and not the author to remain the major selling point. The last majorly successful computer game was Neverwinter Nights, the single player game, and it's sequel; DDO and NWO haven't been failures, but they haven't been spectacular successes either. The board games are largely in the same scenario; they are doing well, but both the D&D boardgames and increasingly Hasbro in general is getting drowned out by all the other board game producers out there. The minis line has all but died out, though not entirely. Let's not even talk about the attempts to get into the movie business so far. Even in regards to the core game itself, 4E largely failed to capitalize on the wealth of worlds and lore built up by earlier editions.
In short, the brand may be recognizable to a significant extent of the general public, not a small feat for a niche game, but it's been stagnant for quite a while now in terms of actual development or usage of that name recognition, and it's going to take significant resources to jump start pretty much all of the above. Even the core game is no longer a product they can simply put out there and expect to sustain itself without ongoing marketing support, not with Pathfinder gaining just as much visibility in the core market and a growing visibility in the general market, not to mention all the other options easily found by anyone who does even a half hearted search for alternatives. If WotC is willing to invest in the not just the initial release of the new edition, but long term, on-going, active support of the brand, they can still capitalize on what they are sitting on, but continued stagnation, or even perceived stagnation, of the brand like we've seen since the late 3.5 period, which is what is likely to happen if Next cannot sustain a high level of interest, will cause a considerable amount of harm to the capabilities of both WotC and Hasbro to utilize the name recognition anytime in the near future, meaning that both of them may well agree that the best thing to do is simply shelve it for a while and see what happens 10, 15 years down the road like they did with Transformers, letting the existing novel lines and computer games to continue as long as the authors and developer companies are willing to sustain them, but not putting out much of anything new. That means a lot is still riding on Next; it may not be the last line of defense before complete failure, but given the decline of Hasbro in it's traditional markets, and WotC's notable lack of new product lines and brands themselves, a continued stagnation of the D&D brand is going to become more and more noticeable to both Hasbro and WotC, something that most certainly cannot aid the brand any.
Another point to consider is that while Transformers may not have been a consistently big deal since the 80's, even in the late 90's, they were still making new Transformer cartoons that got noticed well enough to justify their existence. For D&D to survive in a similar fashion, WotC has to find a way to ensure that at least some notable new content is being put out on a fairly regular basis, and expecting decade old authors and characters to carry the brand is not going to be enough; a fair number of those fans already probably identify more with the author or character than they do the brand at this point, and that number will only grow if the novels are the only notably successful product line. Next doesn't have to do 3.x well in terms of sales and sustainment, but it certainly has to do a lot better than 4E did in order to provide the necessary basis for even a successful hibernation period of sorts to occur.
