Amr Elsadr poses the questions:

On the other hand, have any proposals suggesting that institutional separation of the IANA function from ICANN been preemptively squashed??
Or is the principle still a viable option that can be promoted??

What this announcement does is set a deadline on what has to be done, in the absence of delays by unforeseen forces at play. The key implication is to shift the discussions from "What changes" and "Why the changes" to the "How to do this" while honoring the four stated principles and producing a set of viable and sustainable structures and processes.  That will have ripple effects in structures and processes across the Internet ecosystem. This is more than just replacing one structure by another, and probably nothing has been preempted. A successful outcome will call for heightened stakeholder awareness and engagement, within ICANN, within constituencies, and beyond ICANN.

Sam Lanfranco