I've had a few minor wrist problems, but most of my issues have been with rotators and a knee....which probably came from crappy form and/or trying too hard to play in gym classes with all these college students....
I know there are definitely joint issues for us as well - I had to learn to start taking that glucosamine/chondritin (sp?) pretty regularly and to be patient with setting and meeting my goals, too. I workout at a university gym, so you can imagine how I can see these kids throw the weights around and gain real fast....still, I've been surprised when a few of them have asked me for help, too.
The best thing about this at our age is that it's like investing in some health insurance for our bodies AND minds - after years of not being real athletic, I was amazed to find out I could actually look and feel better than I did at 24...
Of course, I still think the gyms should provide wheelchairs for us old folks when we have a leg day. . .