This sounds like something I could get into! I walk for exercise anyway, but tai chi walking sounds like a way to get a little more "action" into the activity. My ankles quarrel with me when I do too much aerobic style activity, so something low-impact like tai chi makes a lot of sense for me.
I've seen tai chi and I've walked, so combining the two sounds interesting and would make for some nice variety in my workout. I wonder if there are any books or DVDs on the subject for me to look for. I really would like to check it out.