I agree with mbreuer- you still need to get to the airport on time. I always check the Arrivals Board for my gate to see what's coming in and whether it's on time. It's usually a good indicator but there are exceptions. Once, when they posted an inbound at time X and an outbound at X + 15 minutes from the same gate I asked the gate agent. It was a dark and stormy night in EWR, all heck had broken loose and she told me they were making decisions as planes came in as to where they'd go next. It was an honest "we don't know" and I appreciated it.

Second case- leaving MCI to fly to EWR and then to DEL. I had a 3- hour layover in EWR but my flight to EWR was at one point posted 4 hours late. I was on the phone with the travel agent considering alternate bookings when my husband reported that my flight was now "only" 2 hours late. Sure enough, it was. This was also a bad weather day (snowstorm)and I suspect CO didn't want to have to deal with a bunch of misconnect passengers in EWR for international flights so they took another inbound and put us on it. Anyone who left the airport to get dinner and didn't watch their flight status would have been out of luck.