I have a similar question to 1hr 30min layover in Ataturk Airport (Istanbul) , but somewhat different.
My family is flying Lisbon->Istambul->Manila with a transit stop in Ataturk Airport at the end of the month of October. A single ticket covers both legs of the flight.
Turkish airlines just sent a message today, an email in Turkish (God knows why - they speak English), and two SMSes in English telling them their last leg departure was brought forward by 30 minutes.
The point is that they bought that flight because they had 2h20m to do transit, and now they only have 1h50m or less (minus the standard 15 minutes delay for Economy class?), so they should have now 1h35m to change connecting flights.
It is the first time they will be navigating that particular airport.
While the last question states it is possible to do it; my question is a bit different; what steps do they have to take to minimize the problems, and not for instance going by a route different from the transit one? Is Ataturk easy to navigate, and has it plenty of English signs? Any advice on the route to take inside the airport?
In the meanwhile I also found this related question, Need guidance on how to navigate Istanbul Atatürk Airport (IST) , which gives invaluable tips and states it can be a close call if going through security control.