I flew DTW-LHR-DTW on NW a couple weeks ago and both directions were quite empty. Just about everyone had their whole row to themselves. I had the lovely 4-across seats all for me in both directions. Paid Y fare (even though that was pretty expensive TBH) and was able to lie fully flat and actually get some good shut eye for a change. Thats never happened to me before in coach, and I was grateful. The FA's were commenting on the light load all the way...

Also flew DTW-OKC-DTW last weekend and the flights were more fully booked. Still managed both C&D to myself on the CRJ each way though...