I also believe that separating the different IANA roles is a good
approach, protocol parameters can be easily assigned to IETF, IP
address space management to a conglomerate of the RIR's but I don't
see a clear path or good recipient to take the DNS Root Zone
coordination and management role, and it should be outside the
executive management of ICANN.

Unfortunately ICANN is not yet ready, mature and independent to
continue on their role provided by the IANA contract. Also, I don't
have strong arguments about it but I feel that as a principle is not a
good idea to have the same institution do policy development  (or
better said regulation by proxy) and executing the policy, too much
power and influence in only one spot.

Then who is out there that can assume that role without conflict ?, IMHO no one.

It will be hard to believe that the USG will release their control
knob and probably at this time that contract will land on a private
corporation executing the contract under strict USG supervision.

My .02
Jorge