There isn't going to be a diesel. Honda foray into diesel engines for the North American market pretty much died when they were having problems with getting the TSX diesel certified with an AT.
I believe the problem was with the newer high output diesel available in the Euro Accord. Honda can make it pass with the use of UREA, but Honda wanted to sell the motor without requiring UREA.
I believe the regular diesel passes fine, but Honda is taking a wait and see on the demand for diesels.
Me personally, I'd love a diesel. More so than any hybrid.