I think that the negativity in this thread towards what WotC may or may not release to be really overblown. We still haven't heard Gen Con announcements. We still haven't seen what's coming out of that "Open Call". Many here see the core books and adventure paths and assume that since nothing else has been announced that that's all we're going to get.
Complain if we have neither a settings nor magazine announcement by year's end. Otherwise, prognosticating doom and gloom is extremely premature.
While it's true we don't know much about Gen Con or after, we do know pretty much everything up to that and it's quite sparse; any fresh announcements at this point are most likely going to be for Gen Con or later, so the release schedule for everything up to mid to late summer is pretty much known at this point. And I don't really see the level of material in later periods changing that much later on given the small team they have working on it. While we will almost certainly see something, it's not likely to dramatically change the overall level of output, unless the magazines are risen from the grave in some form. That can be taken as negative or as positive as you like, but it pretty much is likely to be reality for the rpg given their repeated statements of wanting to focus on expanding the brand to other markets.
The biggest game changers they could do at this point for the rpg would be an OGL type license or resurrecting the magazines. The former would certainly help the customers and the industry if written well, but probably not do much for WotC or their sales, so even if we do eventually get one, it will probably be far enough in the future to miss the initial surge of interest that could have really helped establish 5E as a true contender in the rpg market, and the magazine is extremely unlikely. I would say if we don't see either of these things by Gen Con, we're not going to see them at all, and the sparse release schedule we see right now will be the norm. That's seems to be fine with WotC, and many posters here, but it will not be enough to keep 5E consistently near the top of any charts. As an rpg, D&D has all but ceded the throne to whoever wants to step up and claim it; right now that's Paizo, but looking forward there are other potential contenders as well. Even with an open license and/or the magazines, the formal brand is not likely to hold the top position consistently.
Prognosticating what you consider to be doom and gloom as 100% guaranteed may be premature, but short of a truly stunning announcement that would most likely be saved for Gen Con, a mostly placeholder rpg for the long term is becoming more and more likely. For better or for worse, the rpg simply isn't likely to get that much attention this go around; that much is already quite clear. The real question is whether or not that turns out to be a good strategy for the brand as a whole or not, and it will take several years to work itself out before we know the answer to that one.