Its a good move but saying it will end Mpesa's dominance is an oversimplification and might not actually happen:
a) The proposals say that money transfers should use "Open Systems", but it doesn't say what these systems are or how they should work. Inter-operable protocols take years to develop and stabilize. Also, openness and availability between collaborators is key. I am also wondering how this will work. Will Safaricom open their transacting servers to other networks? Is it like depositing money in Barclays then withdraw in Stanchart? Baffling. Easy on paper, difficult on the ground.
b) Mpesa dominance is because of the availability of agents across Kenya. Airtel, Yu and Orange don't want to pay agents respectable margins then wonder why no money is flowing to their networks. As long as a subscriber cannot find an agent by merely turning his head and walking 5 meters, they will not use the money service even if regulations and inter-operability is made as open as the sky.
This is going to be rough - i) CBK is incompetent and ii) there is precedence whenever govt wades in tactlessly into telecomms - Number portability - was the magic bullet that was supposed to rein in Safaricom's dominance - only it didn't and it poorly burnt the chap who setup the exchange service.
My 2 cents.