I think this must be liveliest thread on d-addicts! I'm enjoying reading all your thoughts and insights, and I must say, they are more in depth and intense than even the HYD returns thread. Of course also everyone already knew what to expect for HYD, it was just HOW the scriptwriter was going to play it. With ProDai anyone's guess is as good as mine, so that just adds to the whole mystique of the story.
I really don't know what to predict because jdoramas don't always end the way we want them to, unlike kdramas in general.
But I have to agree with the general consensus, that anything short of a happy ending for Kenzou and Rei would make the whole drama totally MEANINGLESS, and I have great confidence that the director and scriptwriter would not be so CRUEL or so TASTELESS in their choice of endings. They have showed enough class and style so far, so it would be totally out of character if they made it a Tada-Rei ending after all.
Having said all that, its still a jdorama, so anything is possible....

: