Jay,
While that question would be fun to guess, I do not believe it helps regarding when does a small theater feel the effect. For example: what if 2 studios decide to stop making film prints available 6 mos before the last studio makes that the decision you ask? Is that possible? Would that effect a theater's business? I can see Universal or Sony or Fox being the first ones to do that while Warner Bros would go much longer. I can't argue with your guess here at all. Which would be 2 more years and you could say Bob is right.
BUT, how practical is that question for the smaller theaters?
How about the month when 50% of the top 10 movies were only digital? This past February saw 8 movies open with more than 2800 locations and all did over $50 million. I believe this scenario could happen a year + before the question you ask. I believe that will next year. Would that effect the small theaters?
Or even more likely: the same scenario as above but 100 or so prints are made for the uninformed big grossers like Mike mentioned. You gross $200k per screen per year sure you get the movie. But how about the $35-50k per screen grossers? Folks like Roxy will still get that print eventually. That will happen in the first quarter of 2013. Would that effect the small theaters?
To me the question needs to be when will a theater in the 3000+ range will have problems opening a movie on the break that it has been accustomed to playing. That is a more important question and harder to measure.
Actually you could even say that day might already be here:
www.bigscreenbiz.com/Forums/The-Lobby/38...r-some-theaters.html
You think having to close down for 2-3 weeks and run less than 50% for another 2 weeks hurt this theater?