not able to answer your question, but I also have ticket to PEK for the Olympics.
Instead of DTW-NRT-PEK, I had to book DTW-PDX-NRT-PEK to get the upgrade in business class (Z). Those seats sell out fast, but if you check often enough, there are not impossible. I had to upgrade pretty much one segment at a time though, as they become available. Right now, I have all segments cleared, both ways, except for that NRT-PEK which isn't a big deal anyways.