Agreed on Telkom style and what they have been doing thus far, however I am in the telecoms industry and from experience etc, there is no way they can launch a network and not come in cheaper (especially being 4th or 5th (if you include Virgin) player in the market) then the existing players, they will crumble.
The differance with mobile and fixed, is they do not have a monopoly and they are not 1st to market, they gona play catch up, so they cant use those tricks in mobile.
I do not see why they cannot launch sooner actually as there is nothing needed from there side, they will be using MTN infrastructure and they already have existing telecom billing dept etc
Personally I def will not be using Telkom, the thought of calling there cust care centre if I have a query is enough to keep me loyal to the existing guys for a long time.