Usually FlightAware is quite accurate about things like inbound flights and the like. I've found it can fall apart when IROPS occur, but I suspect that's because it's relying on a system somewhere that is tracking flights by registration number, and DL (or especially its regional carriers) don't always update the future flights of a plane when IROPS occur.

As an example, I was flying BOS-MEM today on a 9E CR9. As of yesterday afternoon, the plane was supposed to be N912XJ and fly BNA-DTW last night and then DTW-BOS-MEM. Then as of last night, N912XJ was sent out on a 3-hour delayed DTW-PIT flight but still showing that it would fly DTW-BOS-MEM today in spite of the fact that there was no PIT-DTW flight that would get there in time to go DTW-BOS-MEM. I woke up this morning to discover my plane was switched to N933XJ, which flew BWI-DTW-BOS-MEM today.

By the way, if you didn't know it, for DL and most of its connection partners, you can search by registration like this:

http://flightaware.com/live/flight/N912XJ