I will. I'm actually booking tomorrow.
I had an interesting chat with the Medallion desk today. They just had training yesterday on DL's new premium economy. She told me all international flights over 6 hours will have the new seats come June. They will be available for booking in about 2-3 weeks.
To get the premium economy seats you first book coach. After you book you will get an email when the seats are a available online. She then suggested you rush to book them because they are expecting them to fill fast. She told me rows 16-21 on the 767 and the first five rows behind BE on the A333.
We shall see how this goes.