I always thought the assumed people wouldn't be frequenting the theatre as much those times of year because of school , no vacation , etc . If they were to release a major franchise film in September I'm sure it would still do great business .
Of course it will, does anyone seriously think releasing The Dark Knight Rises in October is somehow gonna effect the box office in a substantial way? If anything I think it would be better for new franchises to start in a period outside of that May-July time frame to give them a chance at success. Films are way to front loaded now, it's all about the 'opening weekend' which is pure nonsense, how many times do we see a film rake in over $100 million dollars only to drop 60-65% the following week?