MsE - I had such a bump last year and a lot of pain. I think I caused it by hill running when I was in a fatigued state and over streching it. For me it meant a 6-7 week healing process. The blood flow to the achilles is very limited so it takes a long time to heal. Ice is very good and I suggest to rest and go to the physio. It is fully recoverable and it will not mean an end of running. I know SF is rather hilly in parts maybe best to stick to the Embarcadero as you recover.
Good to see some people are thinking when to run Comrades rather than to run Comrades. It is definently within the capabilities of anyone on here and there is not so much difference to regular marathon training.
Poacher - I'm already starting to think of the next ultra. Maybe the Lakeland 100 would be a long term intention, but not this year. Something around 50 miles first I think.
Upto autumn I want to try to add a bit of speed and finally get a sub 3:15 marathon. Which should be possible now once I am recovered.