Aye, Dragon will always be a mixed bag, and in many respects, the further into the current edition (4th Ed) you go, the more of an issue this will be. Every time a new race, class, or setting is implemented, there's an increased risk that Dragon will provide an article that is not for you. As renaug1 states, wilden are not for me, but for somebody who does play wilden, it becomes a great article.
I'd love to see a runepriest article, but for those who don't play runepriests, the article becomes useless. I think what I would really like to continue to see though are more flavor-oriented articles. Stuff that can be used by a DM as much as by a player. Obviously there still needs to be crunch (heck it becomes a relatively cheap and easy way to produce the equivalent of the Power books -- just over a longer period of time).
I agree too that it would be nice to see more adventures, but who knows where the problem there is coming from. Are they just not getting many quality submissions? Or is there a focus away from them? At least 3 per issue seems like a good goal, particularly since you could then do 1 per tier. We are far enough into 4th Ed's cycle that there are likely plenty of groups looking at Epic level play (though I suppose you could make a good argument for an Epic Adventure every other month).
I too would like to see continued support/supplementals for the assorted campaign settings. Maybe 1 or 2 articles per month and rotating between the settings. That way Eberron fans know that every few months they'll get an article, as will DS fans, FR fans, etc. The majority of each issue can still be dedicated to setting-neutral articles so as to please as many customers as possible.
In the end, every issue will have at least some articles that don't appeal to everyone and the problem is only likely to grow with the new classes and races that get introduce. All in all though, I've been pretty happy. Though I was bummed to see Dungeoncraft go away. Even if most of the advice has been given, just seeing new takes on the approach to running a campaign is helpful. Even the best DM's get writer's block from time to time. I have to say, that I still find DDi to be an incredible value.