I am going to work on properly classic skiing before I move up to skate (plus I don't want to invest in another set of gear). Skate is beautiful to watch. It looks so intense too.
I think rowing and cross country skiing are the best workouts a person can get! I row for my warm up but I don't have the patience to do more than an hour without a team.
I got back into cross country a few years back. I have my own gear now but I am not particularly fast. I never felt that biking really got me into good shape for it though. I'm not particularly fast but I go to family style places and so I feel fast. I think I should work on my technique with some classes. that oughtta help.