I agree that redundancy is important, bu EASSy runs up the east coast, so it doesn't offer a true alternative to SEACOM (both run through Mtunzini and the Suez Canal area). WACS should provide a better option when it comes online (2011?)
SA has an oversupply on international cables (too many built at the same time!) At the same time there is not enough competition on domestic cables and local-loop. At present EASSy is much more important for East African countries. It also possible that local ISP's are waiting for the cable ppl to 'feel the pain' before they negotiate...
All these projects take a long time to be tested (remember SEACOM's teething problems!) Signing long-term contracts and peering agreements requires careful planning. Its not like plugging in a light-bulb - more like a nuclear power station!