Based on these three articles, things may not be looking good for the 3-D format.
Chris Hewitt has written this piece for the St. Paul Pioneer Press on the disorienting effects of 3-D films.
This piece by Gloria Goodale from the Christian Science Monitor tries to account for the lack of box office on this summer's 3-D films.
And this piece by Michael Cieply of the New York Times tells of a growing backlash against 3-D from audiences and filmmakers.
I'm not sure if this is a sign of an actual shift or just a series of articles jumping on a critical bandwagon. I suspect that if the upcoming films continue to do poorly, or at least do not make enough to justify the extra expense of shooting or converting into 3-D, the format could be restrained to only major releases.