Okay, just to prove that the "take your hummingbird feeder in on Labor Day" is bunk, we still have hummingbirds coming to our feeder: Not only that, but someone who lives in Duluth, MN reported a hummingbird at his feeders yesterday. This is normal hummingbird movement this time of year and good reason to keep the feeders out--get that last reminder of summer before they head south across the Gulf of Mexico.
Speaking of hummingbird migration, Scott Weidensaul mentioned there is a study he and others are conducting on the increased number of western hummingbirds that are showing up in the eastern U.S. (we just had a green-breasted mango in Beloit, WI).
The researchers are banding hummers when they can and Scott is theorizing that we may be seeing a new migratory route being developed by some of these populations. A route that takes them from the western US across the continent to the east coast and then south. He noted that many of these birds are turning up later in the season. Another reason to keep those hummingbird feeders out.