Committing to the HBS/HKS joint degree

This makes no sense to me. Why would you let a recommendation letter stand between you and what you want to pursue in life?

Even in a worst case scenario, which is admittedly imperfect - you have a few choices -

* Use the same recommendations that you did for HBS with a note explaining why you were unable to get new ones
* Leverage whoever wrote your HBS ones to write the other ones
* Find someone else to do it - coworker, peer, old boss, new boss, client, whatever
* Find last year's rec questions, ask your the recs to write a rec now -- just do it in letter form (a few pages) addressing those questions as much as possible. If this years are different, simply note that your reco folks were only available before the app was published and you are thus submitting a letter rec. Or dont explain it at all.

I can't fathom how you would let something so tiny get in the way of what you want.