This was unexpected, but welcome. I booked an LAX-AMS roundtrip a few weeks ago for mid-March. I booked in "B" and was able to upgrade the LAX-DTW portion of my return with miles, but no luck with DTW-LAX. I got the "Upgrade Status" e-mail today. I figured I'd end up in first on that flight eventually, but it's nice to have it confirmed so soon.