I hope you're the exception, but all my classmates were denied in the span of a couple days. I imagine it has something to do with when the project receives word from the 'chosen one.'
I contacted my old department manager at MSKCC and told them I didn't get the fellowship and they were surprised to say the least. While completely arbitrary and purely conjecture, my manager thought it had something to do with having 'too much experience' for the project; the project PI wouldn't be meeting the goals of the fellowship by training someone who already has industry experience with the work. The Fellowship is intended to train a relatively bright, but naive student (one who hasn't had a terrible amount of experience with the specific project) to give them a 'taste' of translational medicine. For those who had near identical experience and training with their selected projects and were not selected for the Fellowship, it might have come down to idea of: why train someone who has already been trained? It would not serve the educational goals of the PI and program. Honestly, it sucks for those who applied with applicable experience and could hit the ground running.
I guess I won't be in the city this summer.