I think that it is safe to conclude that withholding the 50k note distribution until the end of January or even in February is because if they did issue them now the locals would just squirrel the large bills away in their mattresses just as they are doing with the 25k notes.
Having said that, however, it is also my view that the CBI/IMF must have plans in place to get an FDIC type of law in place prior to the end of January. Once that law is passed and in place then confidence in banking will return. As the people bring their 25k notes out of the mattresses they can be either deposited or exchanged for 50k notes.
In either case, the 25k notes get released back to the CBI who can burn them, thereby reducing the total money supply and allowing for upward pressure on the value of the dinar.
I conclude, therefore, that we should begin to see a rise in the value of the dinar by early February, including, hopefully, a change in the exchange rate regime to a float.