Darren, pegasus, here's (not very favorable)imput from AA's RTW desk from someone very knowledgeable about African routings and the current rules.

1. Originating JNB. No backtracking via JNB. The only available African destinations from JNB therefore are CPT and HRE (and you must continue on to LHR from there). In effect you get to use only 1 of your 4 segments.

2. No backtracking through LHR from southern Africa to any African destination. (Includes Ghana and Nigeria).

3.Regional Air flights operated by Air Kenya ARE permitted so you could do JNB-HRE-NB0-SEZ-LHR.

As I see it that's it. No Comair destinations other than CPT or HRE and no way to get to MRU or any of the rest of southern or west Africa. You can gain a little flexibility by originating CPT but not much.