I got back from my trip tonight, and I thought I would share my results with the group.
On Tuesday, I took my non-stop AA BOS-ORD ticket to the NW ticket counter in BOS, where the agent seemed to immediately know what I was talking about when I mentioned the BUMP program. He had to call AA to release control of my e-ticket, but quickly confirmed my outbound and return travel on NW metal BOS-DTW-ORD-DTW-BOS. I was very pleased at how smoothly it happened.
One interesting thing was that even though my AA ticket was in N class, NW booked me in Y class on the outbound, and Q class on the return.
All in all, it worked great, and I was very pleased with how the program actually worked.
lopez151