Death of a software developer

I've just started my career as a software developer and I already imagine my impending doom. What happens when my knowledge is obsolete and I no longer can keep up with whats new? What will I do then? I know that this will happen, maybe not tomorrow, but in 10-15 years if I'm lucky. I can do it like others and just stick around, pretending everything is okay while the situation keep getting worse. Some switch positions in their company and becomes sales persons or project managers. That is not something for me. I don't have the social skills of a sales person and the responsibilities of a project manager would probably choke me to death. I must say that I'm quite impressed by the social skills of all sales persons I know and project managers have my unending gratitude of making every workday a little bit easier. It was suggested to me I'd become an architect, but I don't really understand what they do that I don't do today in my daily work. So how would that help in my more and more declining state of technical skills? It would just be another way to grab hold on what once was, and try to boss with my "superior knowledge" of a dead language over those who knows better. I could become "the angry tester". That would suit me pretty well. It would also be a recognition of defeat -I do no longer have sufficient technical skills to be a productive developer. The question is then: would I be sufficient as a QA person? This is a bit early to plan for these things, but it's never to early to just look up and see what's coming. I'd rather see my doom coming slowly from afar, than getting an unexpected immediate moment of truth.