TigerLily, if Afrikaans is similar to Dutch then you'll have an advantage (since Dutch isn't massively hard to decipher if you speak German and English).
Bryan, I did German years ago in school (O-level), didn't use it for years, but found the basics of grammar came back fairly quickly when I moved to Germany (also years ago). I would say, having lived in various German-speaking places for a good part of my life, that this is the biggest problem that you are going to have if you didn't do it as a kid since there is all kind of fun and games with sentence construction and word order, etc.
I know people who work in Zürich and who get along fine with some tourist German they have picked up (there are people who get along fine as non-German speakers). If that's the kind of level you are aiming at then do some study before you leave and try a night class for foreigners once you get there (there are plenty around since there are loads of foreign workers aiming for work permits). The problem there is that you know how to buy stuff in supermarkets and order a beer but you never get further because you don't know the basics of the grammar.
If you want to learn German seriously, start now and try to get into some basic grammar as a background for when you leave. Then take the night classes when you get there and try to speak German as much as possible to your colleagues and neighbours (who will often have unnervingly good English). Like most nationalities, natives love it if someone makes an effort to learn their language and speak it at what ever basic level.
Just try to avoid getting one of those horrible Schwitzerdütsch accents. I worked in the French part of Switzerland when I first went abroad and the French still laugh at my accent.
hahaha
