Supposing that the British column at Isandlwana hadn't majorly screwed things up, instead managing to secure a victory (or at least beat off the Zulu assault with acceptable losses), what sort of effects would we see on how the rest of the war plays out?
The British learned a great many lessons through the defeat at Isandlwana (having enough ammo at hand, setting up lagers when possible, etc), so perhaps those won't be taken to heart if they manage to survive the battle. Also, any ideas about how this would affect the British public and government's opinion of the war?